Death's End

Deterrence Era, Year 12 Bronze Age

It was now possible to see the Earth with the naked eye from the view window of Bronze Age. As the ship decelerated, those who weren’t on duty came to the open space at the stern to observe the Earth through the wide portholes.

At this distance, the Earth still resembled a star, but it was possible to see a pale blue in its glow. The final deceleration stage had begun, and as the stellar drive came online, the crew, who had been floating in zero gravity, drifted toward the portholes like leaves falling in autumn, and finally landed against the broad sheets of glass. The artificial gravity generated by deceleration gradually increased until it reached 1G. The portholes now formed the floor, and the people lying down felt the weight like the embrace of Mother Earth ahead of them. Excitement echoed around the chamber.

“We’re home!”

“Can you believe it?”

“I’ll get to see my kids again.”

“We can have kids!”

When Bronze Age left the Solar System, the law had dictated that no one could be born on the ship unless someone died.

“She said she’d wait for me.”

“If you’ll have her! You’re now a hero of the human race; you’ll have a flock of pretty girls after you.”

“Oh, I haven’t seen flocks of birds in ages!”

“Doesn’t everything we’ve been through seem like a dream?”

“I feel like I’m dreaming now.”

“I’m utterly terrified of space.”

“Me too. I’m retiring as soon as we get back. I’m going to buy a farm and spend the rest of my life on solid ground.”

It had been fourteen years since the complete destruction of the Earth’s combined fleet. The survivors, after engaging in separate internecine battles of darkness, cut off all contact with the home planet. However, for a year and a half thereafter, Bronze Age continued to receive transmissions from Earth, most of which were surface radio communications, but which also included some transmissions intended for space.

And then, at the beginning of November in Year 208 of the Crisis Era, all radio transmissions from Earth ceased. Every frequency fell silent, as though the Earth was a lamp that had been suddenly shut off.

Excerpt from A Past Outside of Time Nyctohylophobia

When humanity finally learned that the universe was a dark forest in which everyone hunted everyone else, the child who had once cried out for contact by the bright campfire put out the fire and shivered in the darkness. Even a spark terrified him.

During the first few days, even mobile phone use was forbidden, and antennas around the world were forcibly shut down. Such a move, which would have once caused riots in the streets, was widely supported by the populace.

Gradually, as reason was restored, so were the mobile networks, but severe restrictions regarding electromagnetic radiation were put in place. All radio communications had to operate at minimum power, and any violators risked being tried for crimes against humanity.

Most people surely understood that these reactions were excessive and meaningless. The peak of the Earth’s projection of electromagnetic signals into space had occurred during the age of analog signals, when television and radio transmission towers operated at high power levels. But as digital communication became prevalent, most information was transmitted via wires and optical cables, and even radio transmissions for digital signals required far less power than analog signals. The amount of electromagnetic radiation spilling into space from the Earth had fallen so much that some pre-Crisis scholars had fretted that the Earth would become impossible to discover by friendly aliens.

Electromagnetic waves are, moreover, the most primitive and least power-efficient method of transmitting information in the universe. Radio waves attenuate and degrade rapidly in the vastness of space, and most electromagnetic signals spilling from the Earth could not be received beyond two light-years. Only something like the transmission by Ye Wenjie, which relied on the power of the sun as an antenna, could be intercepted by listeners among the stars.

As humanity’s technology advanced, two far more efficient methods of signaling became available: neutrinos and gravitational waves. The latter was the main method of deterrence that humanity later deployed against Trisolaris.

The dark forest theory had a profound impact on human civilization. That child sitting by the ashes of the campfire turned from optimism to isolation and paranoia, a loner in the universe.

Deterrence Era, Year 12 Bronze Age

Most of the crew aboard Bronze Age attributed the sudden cessation of all signals from the Earth to the complete conquest of the Solar System by Trisolaris. Bronze Age accelerated and headed for a star with terrestrial planets twenty-six light-years away.

But ten days later, Bronze Age received a radio transmission from Fleet Command. The transmission had been sent simultaneously to Bronze Age and Blue Space, which was at the other end of the Solar System. The transmission gave a brief account of what had happened on Earth and notified them of the successful creation of a deterrence system to defend against Trisolaris. The two ships were ordered to return to Earth immediately. Moreover, Earth had taken great risks to send out this message to the lost ships; it would not be repeated.

At first, Bronze Age dared not trust this message—wasn’t it possible that it was a trap set by those who had conquered the Solar System? The warship stopped accelerating and repeatedly queried Earth for confirmation. No reply ever came, as Earth maintained radio silence.

Just as Bronze Age was about to begin accelerating away from home again, the unimaginable happened: A sophon unfolded into low dimensions on the ship, establishing a quantum communication channel with Earth. Finally, the crew received confirmation of all that had occurred.

The crew found that, as some of the only survivors of the holocaust suffered by the combined space forces of Earth, they were now heroes of the human race. The whole world awaited their return with bated breath. Fleet Command awarded all members of the crew with the highest military honors.

Bronze Age began its return voyage. It was currently in outer space, about twenty-three hundred AU from the Earth, far beyond the Kuiper Belt but still some distance from the Oort Cloud. As it was cruising near maximum speed, deceleration consumed most of its fusion fuel. Its journey toward the Earth had to be conducted at a low cruising speed, and took eleven years.

As they finally neared Earth, a small white dot appeared ahead of them and quickly grew. It was Gravity, the warship that had been dispatched to welcome Bronze Age.

Gravity was the first stellar-class warship built after the Doomsday Battle. Deterrence-Era spaceships were no longer constructed along fixed body plans. Rather, most large spaceships were constructed out of multiple modules that could be assembled into various configurations. But Gravity was an exception. It was a white cylinder, so regular that it seemed unreal, like a basic shape dropped into space by mathematical modeling software, a platonic ideal rather than reality.

If the crew of Bronze Age had seen the gravitational wave antennas on the Earth, they would have recognized Gravity as an almost perfect replica of them. Indeed, the entire hull of Gravity was a large gravitational wave antenna. Like its twins on the Earth’s surface, the ship was capable of broadcasting gravitational wave messages toward all corners of the universe at a moment’s notice. These gravitational wave antennas on Earth and in space comprised humanity’s dark forest deterrence system against Trisolaris.

After another day of coasting, Bronze Age, escorted by Gravity, entered geosynchronous orbit and slowly sailed into the orbital spaceport. Bronze Age’s crew could see dense crowds filling the broad expanse of the habitat sector of the spaceport like the opening ceremony of the Olympics or the Hajj in Mecca. The warship drifted through a colorful snowstorm of bouquets. The crew looked through the crowd for their loved ones. Everyone seemed to have tears in their eyes, crying out in joy.

With a final tremor, Bronze Age came to a complete stop. The captain gave a status report to Fleet Command and declared his intent to leave a skeleton crew behind on the ship. Fleet Command replied that the priority was to quickly reunite all members of the crew with their loved ones. There was no need to leave anyone behind on the ship. Another captain from the fleet boarded the ship with a small duty team who greeted everyone they encountered with tearful embraces.

It was unclear from the duty team’s uniforms which of the three space fleets they belonged to, but they explained to those aboard the ship that the new Solar System Fleet was a single, unified force, and all those who had been part of the Doomsday Battle—including all the men and women aboard Bronze Age—would be key figures in the new fleet.

“In our lifetimes, we will conquer Trisolaris and open up a second solar system for human colonization!” the fleet captain said.

Someone replied that they found space too terrifying and they would rather remain on the Earth. The fleet captain said that was perfectly acceptable. As heroes of humanity, they were free to choose their own paths in life. However, after a bit of R&R, they might change their minds. He, for one, hoped to see this famed warship in action again.

The crew of Bronze Age began to disembark. Everyone entered the habitable region of the spaceport through a long passageway. Open space stretched around the crew. In contrast to the air on the ship, the air here smelled fresh and sweet, like after a rainstorm. Against the background of the spinning blue globe that was the Earth, the joyous shouts of the welcoming crowd filled the expansive area.

Per a request from the fleet captain, the captain of Bronze Age conducted a roll call. At the fleet captain’s insistence, the roll call was repeated, to confirm that every member of the crew had disembarked and was present and accounted for.

Then there was silence.

Although the celebrating crowd around them continued to dance and wave their arms, they made no sound. All that anyone from Bronze Age could hear was the fleet captain’s voice. His face still bore a kind smile, but in that eerie silence, his voice sounded as sharp as the edge of a sword.

“You’re hereby informed that you have been dishonorably discharged. You are no longer members of the Solar System Fleet. But the stain you have brought upon the fleet can never be erased! You will never see your loved ones again, because they have no wish to see you. Your parents are ashamed of you, and most of your spouses have long ago divorced you. Even though society has not discriminated against your children, they spent the past decade growing up in the shadow of your disgrace. They despise you!

“You are hereby transferred to Fleet International’s justice system.”

The fleet captain left with his team. Simultaneously, the celebratory crowd disappeared and was replaced by darkness. A few roving spotlights revealed the ranks of fully armed military police surrounding the crew of Bronze Age. Standing on platforms around the broad square, they aimed their guns at the crew.

Some members of the crew turned around and saw that the bouquets of flowers floating around Bronze Age were real, not holographic mirages. But now they made the warship seem like a giant coffin about to be buried.

Power to the magnetic boots worn by the crew was cut off, and they floated up in free fall, like a bunch of helpless target dummies.

A cold voice spoke to them from somewhere. “All armed crew members must immediately relinquish your weapons. If you do not cooperate, we cannot guarantee your safety. You’re under arrest for murder in the first degree and crimes against humanity.”

Deterrence Era, Year 13 Trial

The Bronze Age case was tried by a Solar System Fleet court-martial. Although Fleet International’s main facilities were located near the orbit of Mars, the asteroid belt, and the orbit of Jupiter, due to the intense interest in the case from Earth International, the trial was held at the fleet base in geosynchronous orbit.

To accommodate the numerous observers from Earth, the base spun to generate artificial gravity. Outside the broad windows of the courtroom, blue Earth, bright Sun, and the silvery brilliance of the stars appeared in succession, a cosmic metaphor for the contest of values. The trial lasted a month under these shifting lights and shadows. Excerpts from the trial transcript follow.

In the end, Captain Neil Scott and six other senior officers were convicted of murder and crimes against humanity and sentenced to life imprisonment. Of the remaining 1,768 members of the crew, only 138 were declared innocent. The rest received sentences ranging from twenty to three hundred years.

The Fleet International prison was located in the asteroid belt, between the orbits of Mars and Jupiter. Thus, the prisoners had to leave Earth again. Although Bronze Age had reached geosynchronous orbit, the prisoners were doomed never to travel the last thirty thousand kilometers of their 350-billion-kilometer voyage home.

As the prisoner transport ship accelerated, they once again drifted and fell against the portholes at the stern, like fallen leaves doomed to never reach the root of the tree. They looked outward as the blue globe that had haunted their dreams shrank and, once again, became just another star.

Before departing the fleet base, former Commander Rovinski, former Lieutenant Commander Schneider, and about a dozen other officers returned under guard to Bronze Age for the last time to assist with some details of the handover of the ship to her new crew.

For more than a decade, this ship had been their entire world. They had carefully decorated the inside with holograms of grasslands, forests, and oceans; cultivated real gardens; and built fishing ponds and water fountains, turning the ship into a real home. But now, all that was gone. All traces of their existence on the ship had been wiped away. Bronze Age was once again just a cold stellar warship.

Everyone they encountered in the halls looked at them coldly or simply ignored them. When they saluted, they made sure their eyes did not waver, to make it clear to the prisoners that the salute was for the military police escorting them only.

Schneider was brought to a spherical cabin to discuss technical details of the ship’s targeting system with three officers. The three officers treated Schneider like a computer. They asked him questions in an emotionless voice and waited for his answers. There was not a hint of politeness, and not a single wasted word.

It took only an hour to complete the session. Schneider tapped the floating control interface a few times, as though closing some windows out of habit. All of a sudden, he kicked the spherical wall of the cabin hard, and propelled himself to the other end of the chamber. Simultaneously, the walls shifted and divided the cabin into two halves. The three officers and the military policeman were trapped in one half, and Schneider was alone in the other.

Schneider brought up a floating window. He tapped on it, his fingers a blur. It was the control interface for the communications system. Schneider brought the ship’s high-powered interstellar communications antenna online.

A faint pop. A small hole appeared in the cabin wall, and the cabin was filled with white smoke. The barrel of the military policeman’s gun poked through the hole and aimed at Schneider.

“This is your last warning. Stop what you’re doing immediately and open the door.”

“Blue Space, this is Bronze Age.” Schneider’s voice was quiet. He knew how far his message could travel had nothing to do with how loudly he spoke.

A laser beam shot through Schneider’s chest. Red steam from vaporized blood erupted from the hole. Surrounded by a red fog made of his own blood, Schneider croaked out his last words:

“Don’t come back. This is no longer your home!”

Blue Space had always responded to Earth’s entreaties with more hesitation and suspicion than Bronze Age had, so they had only been decelerating slowly. Thus, by the time they received Bronze Age’s warning, they were still heading away from the Solar System.

After Schneider’s warning, Blue Space instantly shifted from decelerating to accelerating full speed ahead.

When Earth received the intelligence report from the sophons of Trisolaris, the two civilizations had a shared enemy for the first time in history.

Earth and Trisolaris were comforted by the fact that Blue Space didn’t currently possess the ability to engage in dark forest deterrence against the two worlds. Even if it tried to broadcast the locations of the two solar systems to the universe at full power, it would be almost impossible for anyone to hear it. To reach Barnard’s Star, the nearest star that Blue Space could use as a superantenna to repeat Ye Wenjie’s feat, would take three hundred years. However, it hadn’t shifted its course toward Barnard’s Star. Instead, it was still heading toward NH558J2, which it wouldn’t reach for two thousand more years.

Gravity, as the only Solar System ship capable of interstellar flight, immediately began to pursue Blue Space. Trisolaris brought up the idea of sending a speedy droplet—formally, it was called a strong-interaction space probe—to pursue and destroy Blue Space. But Earth unequivocally refused. From humanity’s perspective, Blue Space should be dealt with as a matter of internal affairs. The Doomsday Battle was humanity’s greatest wound, and after more than a decade, the pain had not lessened one whit. Permitting another droplet attack on humans was absolutely politically unacceptable. Even though the crew of Blue Space had become aliens in the minds of most people, only humanity should bring them to justice.

Out of consideration for the ample time that remained before Blue Space could become a threat, Trisolaris acquiesced. However, Trisolaris emphasized that, since Gravity possessed the ability to broadcast via gravitational waves, its security was a matter of life and death for Trisolaris. Therefore, droplets would be sent as escorts, but would also ensure an overwhelming advantage against Blue Space.

Thus, Gravity cruised in formation with two droplets a few thousand meters away. The contrast between the sizes of the two ship types couldn’t be greater. If one pulled back far enough to see the entirety of Gravity, the droplets would be invisible. And if one pulled close enough to a droplet to observe it, its smooth surface would clearly reflect an image of Gravity.

Gravity was built about a decade after Blue Space. Other than the gravitational wave antenna, it was not significantly more advanced. Its propulsion systems, for example, were only slightly more powerful than Blue Space’s. Gravity’s confidence in the success of their hunt was due to their overwhelming advantage in fuel reserves.

Even so, based on the ships’ current velocities and accelerations, it would take fifty years for Gravity to catch Blue Space.

Deterrence Era, Year 61 The Swordholder

Cheng Xin gazed up at her star from the top of a giant tree. It was why she had been awakened.

During the brief life of the Stars Our Destination Project, a total of fifteen individuals were granted ownership of seventeen stars. Other than Cheng Xin, the other fourteen owners were lost to history, and no legal heirs could be located. The Great Ravine acted like a giant sieve, and too many did not make it through. Now, Cheng Xin was the only one who held legal title to a star.

Though humanity still hadn’t begun to reach for any star beyond the Solar System, the rapid pace of technological progress meant that stars within three hundred light-years of the Earth were no longer of mere symbolic value. DX3906, Cheng Xin’s star, turned out to have planets after all. Of the two planets discovered so far, one seemed very similar to Earth based on its mass, orbit, and a spectrum analysis of its atmosphere. As a result, its value rose to stratospheric heights. To everyone’s surprise, they discovered that this star already had an owner.

The UN and the Solar System Fleet wanted to reclaim DX3906, but this couldn’t be done legally unless the owner agreed to transfer the title. Thus Cheng Xin was awakened from her slumber after 264 years of hibernation.

The first thing she found out after emerging from hibernation was this: As she had expected, there was no news whatsoever about the Staircase Program. The Trisolarans had not intercepted the probe, and they had no idea of its whereabouts. The Staircase Program had been forgotten by history, and Tianming’s brain was lost in the vastness of space. But this man, this man who had merged into nothingness, had left a real, solid world for his beloved, a world composed of a star and two planets.

A Ph.D. in astronomy named 艾 AA[3] had discovered the planets around DX3906. As part of her dissertation, AA had developed a new technique that used one star as a gravitational lens through which to observe another.

To Cheng Xin, AA resembled a vivacious bird fluttering around her nonstop. AA told Cheng Xin that she was familiar with people like her, who had come from the past—known as “Common Era people” after the old calendar—since her own dissertation advisor was a physicist from back then. Her knowledge of Common Era people was why she had been appointed as Cheng Xin’s liaison from the UN Space Development Agency as her first job after her doctorate.

The request from the UN and the fleet to sell the star back to them put Cheng Xin in an awkward position. She felt guilty possessing a whole world, but the idea of selling a gift that had been given to her out of pure love made her ill. She suggested that she could give up all claim of ownership over DX3906 and keep the deed only as a memento, but she was told that was unacceptable. By law, the authorities could not accept such valuable real estate without compensating the original owner, so they insisted on buying it. Cheng Xin refused.

After much reflection, she came up with a new proposal: She would sell the two planets, but retain ownership of the star. At the same time, she would sign a covenant with the UN and the fleet granting humanity the right to use the energy produced by the star. The legal experts eventually concluded that this proposal was acceptable.

AA told Cheng Xin that since she was only selling the planets, the amount of compensation offered by the UN was much lower. But it was still an astronomical sum, and she would need to form a company to manage it properly.

“Would you like me to help you run this company?” AA asked.

Cheng Xin agreed, and AA immediately called the UN Space Development Agency to resign.

“I’m working for you now,” she said, “so let me speak for a minute about your interests. Are you nuts?! Of all the choices available to you, you picked the worst! You could have sold the star along with the planets, and you would have become one of the richest people in the universe! Alternatively, you could have refused to sell, and kept the entire solar system for yourself. The law’s protection of private property is absolute, and no one could have taken it away from you. And then you could have entered hibernation and woken up only when it’s possible to fly to DX3906. Then you could go there! All that space! The ocean, the continents… you can do whatever you want, of course, but you should take me with you—”

“I’ve already made my decision,” Cheng Xin said. “There’s almost three centuries separating us. I don’t expect us to understand each other right away.”

“Fine.” AA sighed. “But you should reevaluate your conception of duty and conscience. Duty drove you to give up the planets, and conscience made you keep the star, but duty again made you give up the star’s energy output. You’re one of those people from the past, like my dissertation advisor, torn by conflict between two ideals. But, in our age, conscience and duty are not ideals: an excess of either is seen as a mental illness called social-pressure personality disorder. You should seek treatment.”

Even with the glow from the lights of the city below, Cheng Xin easily found DX3906. Compared to the twenty-first century, the air was far clearer. She turned from the night sky to the reality around her: She and AA stood like two ants on top of a glowing Christmas tree, and all around them stood a forest of Christmas trees. Buildings full of lights hung from branches like leaves. But this giant city was built on top of the earth, not below it. Thanks to the peace of the Deterrence Era, humanity’s second cave-dwelling phase had come to an end.

They walked along the bough toward the tip. Each branch of the tree was a busy avenue full of floating translucent windows filled with information. They made the street look like a varicolored river. From time to time, a window or two left the traffic in the road and followed them for a while, and drifted back into the current when AA and Cheng Xin showed no interest. All the buildings on this branch-street hung below. Since this was the highest branch, the starry sky was right above them. If they had been walking along one of the lower branches, they would be surrounded by the bright buildings hanging from the branch above, and they would have felt like tiny insects flying through a dream forest, in which every leaf and fruit sparkled and dazzled.

Cheng Xin looked at the pedestrians along the street: a woman, two women, a group of women, another woman, three women—all of them were women, all beautiful. Dressed in pretty, luminous clothes, they seemed like the nymphs of this magical forest. Once in a while, they passed some older individuals, also women, their beauty undiminished by age. As they reached the end of the branch and surveyed the sea of lights below them, Cheng Xin asked the question that had been puzzling her for days. “What happened to the men?” In the few days since she had been awakened, she had not seen a single man.

“What do you mean? They’re everywhere.” AA pointed at the people around them. “Over there: See the man leaning against the balustrade? And there are three over there. And two walking toward us.”

Cheng Xin stared. The individuals AA indicated had smooth, lovely faces; long hair that draped over their shoulders; slender, soft bodies—as if their bones were made of bananas. Their movements were graceful and gentle, and their voices, carried to her by the breeze, were sweet and tender…. Back in her century, these people would have been considered ultra-feminine.

Understanding dawned on her after a moment. The trend had been obvious even earlier. The decade of the 1980s was probably the last time when masculinity, as traditionally defined, was considered an ideal. After that, society and fashion preferred men who displayed traditionally feminine qualities. She recalled the Asian male pop stars of her own time who she had thought looked like pretty girls at first glance. The Great Ravine interrupted this tendency in the evolution of human society, but half a century of peace and ease brought about by the Deterrence Era accelerated the trend.

“It’s true that Common Era people usually have trouble telling men and women apart at first,” AA said. “But I’ll teach you a trick. Pay attention to the way they look at you. A classical beauty like you is very attractive to them.”

Cheng Xin looked at her, a bit flustered.

“No, no!” AA laughed. “I really am a woman, and I don’t like you that way. But, honestly, I can’t see what’s attractive about the men of your era. Rude, savage, dirty—it’s like they hadn’t fully evolved. You’ll adjust to and enjoy this age of beauty.”

Close to three centuries ago, when Cheng Xin had been preparing for hibernation, she had imagined all kinds of difficulties she would face in the future, but this was something she was unprepared for. She imagined what it would be like to live the rest of her life in this feminine world… and her mood turned melancholic. She looked up and searched for her star.

“You’re thinking of him again, aren’t you?” AA grabbed her by the shoulders. “Even if he hadn’t gone into space and had spent the rest of his life with you, the grandchildren of your grandchildren would be dead by now. This is a new age; a new life. Forget about the past!”

Cheng Xin tried to think as AA suggested and forced herself to return to the present. She had only been here for a few days, and had just grasped the broadest outline of the history of the past three centuries. The strategic balance between the humans and the Trisolarans as a result of dark forest deterrence had shocked her the most.

A thought popped into her mind. A world dedicated to femininity… but what does that mean for deterrence?

Cheng Xin and AA walked back along the bough. Again, a few informational windows drifted along with them, and this time, one drew Cheng Xin’s attention. The window showed a man, clearly a man from the past: haggard, gaunt, messy hair, standing next to a black tombstone. The man and the tombstone were in shadows, but his eyes seemed to glow brightly with the reflected light of a distant dawn. A line of text appeared on the bottom of the screen:

Back during his time, a killer would be sentenced to death.

Cheng Xin thought the man’s face looked familiar, but before she could look more closely, the image had disappeared. In his place appeared a middle-aged woman—well, at least Cheng Xin thought she was a woman. Wearing formal, non-glowing clothes that reminded Cheng Xin of a politician’s, she was in the middle of giving a speech. The text earlier had been a part of the subtitles for her speech.

The window seemed to notice Cheng Xin’s interest. It expanded and began to play the audio accompanying the video. The politician’s voice was lovely and sweet, as though the words were strung together by strands of blown sugar. But the content of the speech was terrifying.

“Why the death penalty? Answer: because he killed. But that is only one correct answer.

“Another correct answer would be: because he killed too few. Killing one person was murder; killing a few or dozens was more murder; so killing thousands or tens of thousands ought to be punished by putting the murderer to death a thousand times. What about more than that? A few hundred thousand? The death penalty, right? Yet, those of you who know some history are starting to hesitate.

“What if he killed millions? I can guarantee you such a person would not be considered a murderer. Indeed, such a person may not even be thought to have broken any law. If you don’t believe me, just study history! Anyone who has killed millions is deemed a ‘great’ man, a hero.

“And if that person destroyed a whole world and killed every life on it—he would be hailed as a savior!”

“They’re talking about Luo Ji,” said AA. “They want to put him on trial.”

“Why?”

“It’s complicated. But basically, it’s because of that world, the world whose location he broadcast to the universe, causing it to be destroyed. We don’t know if there was life on that world—it’s a possibility. So they’re charging him with suspected mundicide, the most serious crime under our laws.”

“Hey, you must be Cheng Xin!”

The voice shocked Cheng Xin. It had come from the floating window in front of her. The politician in it gazed at Cheng Xin, joy and surprise on her face, as though she were seeing an old friend. “You’re the woman who owns that faraway world! Like a ray of hope, you’ve brought the beauty of your time to us. As the only human being ever to possess an entire world, you will also save this world. All of us have faith in you. Oh, sorry, I should introduce myself—”

AA kicked the window and shut it off. Cheng Xin was utterly amazed by the technology level of this age. She had no idea how her own image had been transmitted to the speaker, and no idea how the speaker was then able to pick her out of the billions who were watching her speech.

AA rushed in front of Cheng Xin and walked backwards as they talked. “Would you have destroyed a world to create this form of deterrence? And, more importantly, if the enemy weren’t deterred, would you press the button to ensure the destruction of two worlds?”

“This is a meaningless question. I would never put myself in that position.”

AA stopped and grabbed Cheng Xin by the shoulders. She stared into her eyes. “Really? You wouldn’t?”

“Of course not. Being put in such a position is the most terrifying fate I can think of. Far worse than death.”

She couldn’t understand why AA seemed so earnest, but AA nodded. “That puts me at ease…. Why don’t we talk more tomorrow? You’re tired and should get more rest. It takes a week to completely recover from hibernation.”

The next morning, Cheng Xin got a call from AA.

AA showed up on the screen looking excited. “I’m going to surprise you and take you somewhere cool. Come on up. The car is at the top of the tree.”

Cheng Xin went up and saw a flying car with its door open. She got in but didn’t see AA. The door slid shut noiselessly and the seat molded itself around her, holding her tight like a hand. Gently, the car took off, merging into the streaming traffic of the forest-city.

It was still early, and shafts of sunlight, almost parallel to the ground, flickered through the car as it passed through the forest. Gradually, the giant trees thinned out and, finally, disappeared. Under the blue sky, Cheng Xin saw only grassland and woodland, an intoxicating green mosaic.

After the start of the Deterrence Era, most heavy industries had moved into orbit, and the Earth’s natural ecology recovered. The surface of the Earth now looked more like it did in pre–Industrial Revolution times. Due to a drop in population and further industrialization of food production, much of the arable land was allowed to lie fallow and return to nature. The Earth was transforming into a giant park.

This beautiful world seemed unreal to Cheng Xin. Though awakened from hibernation, she felt as though she were in a dream.

Half an hour later, the car landed and the door slid open automatically. Cheng Xin got out, and the car rose into the air and left. After the turbulence from the propellers subsided, silence reigned over everything, pierced by occasional birdsong from far away. Cheng Xin looked around and found herself in the midst of a group of abandoned buildings. They looked like residential buildings from the Common Era. The bottom half of every building was covered in ivy.

The sight of the past covered by the green life of a new era gave Cheng Xin the sense of reality that she had been missing.

She called for AA, but a man’s voice responded. “Hello.”

She turned and saw a man standing on an ivy-covered second-story balcony. He wasn’t like the soft, beautiful men of this time, but like the men of the past. Cheng Xin seemed to be dreaming again, a continuation of her nightmare from the Common Era.

It was Thomas Wade. He wore a black leather jacket, but he looked a bit older. Perhaps he had gone into hibernation after Cheng Xin, or perhaps he had awakened before her, or both.

Cheng Xin’s eyes were focused on Wade’s right hand. The hand, covered by a black leather glove, held an old Common-Era gun that was pointing at Cheng Xin.

“The bullet in here was designed to be shot underwater,” said Wade. “It’s supposed to last a long time. But it’s been more than two hundred and seventy years. Who knows if it will work?” That familiar smile, the one he wore when he was taking delight in the despair of others, appeared on his face.

A flash. An explosion. Cheng Xin felt a hard punch against her left shoulder and the force slammed her against the broken wall behind her. The thick ivy muffled much of the noise from the gunshot. Distant birds continued to chitter.

“I can’t use a modern gun,” said Wade. “Every shot is automatically recorded in the public security databases now.” His tone was as serene as it had been when he used to discuss routine tasks with her.

“Why?” Cheng Xin didn’t feel pain. Her left shoulder felt numb, as if it didn’t belong to her.

“I want to be the Swordholder. You are my competitor, and you’re going to win. I don’t harbor any ill will toward you. Whether you believe me or not, I feel terrible at this moment.”

“Did you kill Vadimov?” she asked. Blood seeped from the corner of her mouth.

“Yes. The Staircase Program needed him. And now, my new plan does not need you. Both of you are very good, but you’re in the way. I have to advance, advance without regard for consequences.”

Another shot. The bullet went through the left side of Cheng Xin’s abdomen. She still didn’t feel pain, but the spreading numbness made her unable to keep standing. She slid down against the wall, leaving a bright trail of blood on the ivy behind her.

Wade pulled the trigger again. Finally, the passage of nearly three centuries caught up with the gun, and it made no sound. Wade racked the slide to clear the dud out of the chamber. Once again, he pointed the gun at Cheng Xin.

His right arm exploded. A puff of white smoke rose into the air, and Wade’s right forearm was gone. Burnt bits of bone and flesh splattered into the green leaves around him, but the gun, undamaged, fell to the foot of the building. Wade didn’t move. He took a look at the stump of his right arm and then looked up. A police car was diving toward him.

As the police car approached the ground, several armed police officers jumped out and landed in the thick grass waving in the turbulence thrown up by the propellers. They looked like slender, nimble women.

The last one to jump out of the car was AA. Cheng Xin’s vision was blurring, but she could see AA’s tearful face and hear her sobbing explanation.

“…faked my call…”

A fierce wave of pain seized her, and she lost consciousness.

When Cheng Xin woke up, she found herself in a flying car. A film clung to her and wrapped her tightly. She couldn’t feel pain, couldn’t even feel the presence of her body. Her consciousness began to fade again. In a faint voice that no one but herself could hear, she asked, “What is a Swordholder?”

Excerpt from A Past Outside of Time The Ghost of the Wallfacers: The Swordholder

Without a doubt, Luo Ji’s creation of dark forest deterrence against Trisolaris was a great achievement, but the Wallfacer Project that led to it was judged a ridiculous, childish act. Humanity, like a child entering society for the first time, had lashed out at the sinister universe with terror and confusion. Once Luo Ji had transferred control of the deterrence system to the UN and the Solar System Fleet, everyone thought the Wallfacer Project, a legendary bit of history, was over.

People turned their attention to deterrence itself, and a new field of study was born: deterrence game theory.

The main elements of deterrence are these: the deterrer and the deteree (in dark forest deterrence, humanity and Trisolaris); the threat (broadcasting the location of Trisolaris so as to ensure the destruction of both worlds); the controller (the person or organization holding the broadcast switch); and the goal (forcing Trisolaris to abandon its invasion plan and to share technology with humanity).

When the deterrent is the complete destruction of both the deterrer and the deteree, the system is said to be in a state of ultimate deterrence.

Compared to other types of deterrence, ultimate deterrence is distinguished by the fact that, should deterrence fail, carrying out the threat would be of no benefit to the deterrer.

Thus, the key to the success of ultimate deterrence is the belief by the deteree that the threat will almost certainly be carried out if the deteree thwarts the deterrer’s goals. This probability, or degree of deterrence, is an important parameter in deterrence game theory. The degree of deterrence must exceed 80 percent for the deterrer to succeed.

But people soon discovered a discouraging fact: If the authority to carry out the threat in dark forest deterrence is held by humanity as a whole, then the degree of deterrence is close to zero.

Asking humanity to take an action that would destroy two worlds is difficult: The decision would violate deeply held moral principles and values. The particular conditions of dark forest deterrence made the task even harder. Should deterrence fail, humanity would survive for at least one more generation. In a sense, everyone alive would be unaffected. But in the event of deterrence failing, carrying out the threat and broadcasting would mean that destruction could come at any moment, a far worse result than not carrying out the threat. Thus, if deterrence failed, the reaction of humankind as a whole could be easily predicted.

But an individual’s reaction could not be predicted.

The success of dark forest deterrence was founded on the unpredictability of Luo Ji as an individual. If deterrence failed, his actions would be guided by his own personality and psychology. Even if he acted rationally, his own interests might not match humanity’s interests perfectly. At the beginning of the Deterrence Era, both worlds carefully analyzed Luo Ji’s personality and built up detailed mathematical models. Human and Trisolaran deterrence game theorists reached remarkably similar conclusions: Depending on his mental state at the moment deterrence failed, Luo Ji’s degree of deterrence hovered between 91.9 percent and 98.4 percent. Trisolaris would not gamble with such odds.

Of course, such careful analysis wasn’t possible immediately after the creation of dark forest deterrence. But humanity quickly reached this conclusion intuitively, and the UN and the Solar System Fleet handed the authority to activate the deterrence system back to Luo Ji like a hot potato. The entire process from Luo Ji turning over the authority to getting it back took a total of eighteen hours. Yet that would have been long enough for droplets to destroy the ring of nuclear bombs surrounding the Sun and deprive humanity of the ability to broadcast their locations. The Trisolarans’ failure to do so was widely considered their greatest strategic blunder during the war, and humanity, covered in cold sweat, let out a held breath.

Since then, the power to activate the dark forest deterrence system had always been vested in Luo Ji. His hand first held the detonation switch for the circumsolar ring of nuclear bombs, and then the switch for the gravitational wave broadcast.

Dark forest deterrence hung over two worlds like the Sword of Damocles, and Luo Ji was the single hair from a horse’s tail that held up the sword. Thus, he came to be called the Swordholder.

The Wallfacer Project did not fade into history after all. Humanity could not escape the Wallfacers’ ghost.

Although the Wallfacer Project was an unprecedented anomaly in the history of humankind, both dark forest deterrence and the Swordholder had precursors. The mutual assured destruction practiced by NATO and the Warsaw Pact during the Cold War was an example of ultimate deterrence. In 1974, The Soviet Union initiated the Perimeter System (Russian Система «Периметр»), or “Dead Hand.” This was intended to guarantee that the Soviet Union possessed a viable second-strike capability in the event that an American-led first strike eliminated the Soviet government and high-level military command centers. The system relied on a monitoring system that gathered evidence of nuclear explosions within the Soviet Union; all the data was transmitted to a central computer that interpreted the data and decided whether to launch the Soviet Union’s nuclear arsenal.

The heart of the system was a secret control chamber hidden deep underground. If the system determined that a counterstrike must be launched, an operator on duty would initiate it.

In 2009, an officer who had been on duty in the room decades earlier told a reporter that at the time, he was a twenty-five-year-old junior lieutenant, freshly graduated from Frunze Military Academy. If the system determined that a strike was necessary, he was the last check before the complete destruction of the world. At that moment, all of the Soviet Union and Eastern Europe would likely be a sea of flames, and all of his loved ones above ground almost certainly dead. If he pushed the button, North America would also turn into hell on Earth in half an hour, and the following nuclear winter would doom all of humanity. He would hold the fate of human civilization in his hand.

Later, he was asked this question many times: If that moment had really arrived, would you have pushed the button?

The first Swordholder in history answered: I don’t know.

Humanity hoped that dark forest deterrence would have a happy ending, like the mutually assured destruction of the twentieth century.

Time passed in this strange balance. Deterrence had been in effect for sixty years, and Luo Ji, who was now over a hundred, still held the switch to initiate the broadcast. His image among the populace had also gradually changed.

Hawks who wished to take the hard line against Trisolaris did not like him. Near the beginning of the Deterrence Era, they advocated imposing more severe conditions on the Trisolarans, with the goal of completely disarming Trisolaris. Some of their proposals were absurd. For instance, one idea was the “naked resettlement” program, which would have demanded that all Trisolarans dehydrate and allow themselves to be transported by cargo ships to the Oort Cloud, where they would be picked up by human spaceships and brought to the Solar System to be stored in dehydratories on Mars or the moon. Thereafter, if the Trisolarans satisfied certain conditions, they would be rehydrated in small batches.

The doves, similarly, did not like Luo Ji. Their primary concern was whether the star 187J3X1, whose location had been broadcast by Luo Ji, had possessed planets that harbored life and civilization. No astronomer from the two worlds could definitively answer this question: It was impossible to prove the affirmative or the negative. But it was certain that Luo Ji could be suspected of having committed mundicide. The doves believed that in order for humanity and Trisolaris to peacefully coexist, the foundation must be universal “human” rights—in other words, the recognition that all civilized beings in the universe had inviolable, fundamental rights. To make such an ideal into reality, Luo Ji must be tried.

Luo Ji ignored them all. He held the switch to the gravitational wave broadcast system and silently stood at the Swordholder post for half a century.

Humanity came to realize that all policies with respect to the Trisolarans had to take the Swordholder into account. Without his approval, no human policy had any effect on Trisolaris. Thus, the Swordholder became a powerful dictator, much like the Wallfacers had.

As time passed, Luo Ji slowly came to be seen as an irrational monster and a mundicidal despot.

People realized that the Deterrence Era was a strange time. On the one hand, human society had reached unprecedented heights of civilization: Human rights and democracy reigned supreme everywhere. On the other hand, the entire system existed within the shadow of a dictator. Experts believed that although science and technology usually contributed to the elimination of totalitarianism, when crises threatened the existence of civilization, science and technology could also give birth to new totalitarianism. In traditional totalitarian states, the dictator could only enact his control through other people, which led to low efficiency and uncertainty. Thus, there had never been a 100 percent effective totalitarian society in human history. But technology provided the possibility for such a super-totalitarianism, and both the Wallfacers and the Swordholder were concerning examples. The combination of supertechnology and a supercrisis could throw humankind back into the dark ages.

But most people also agreed that deterrence remained necessary. After the sophons unblocked the progress of human technology and the Trisolarans began transferring their knowledge to humans, human science had advanced by leaps and bounds. However, compared to Trisolaris, Earth was still behind by at least two or three technology ages. Decommissioning the deterrence system was to be considered only when the two worlds were approximately equal in technology.

There was one more choice: turning over control of the deterrence system to artificial intelligence. This was a choice that had been evaluated seriously, and much effort was expended in researching its feasibility. Its biggest advantage was a very high degree of deterrence. But ultimately, it wasn’t adopted. Handing over the fate of two worlds to machines was a terrifying idea. Experiments showed that AIs tended not to make correct decisions when faced with the complex conditions of deterrence—unsurprising, since correct judgment required more than logical reasoning. Moreover, changing from a dictatorship-by-man to a dictatorship-by-machine wouldn’t have made people feel any better, and was politically worse. Finally, sophons could interfere with AI reasoning. Though no example of such interference had been discovered, the mere possibility made the choice inconceivable.

A compromise was to change the Swordholder. Even without the above considerations, Luo Ji was a centenarian. His thinking and psychological state were becoming more unreliable, and people were growing uneasy that the fate of both worlds rested in his hands.

Deterrence Era, Year 61 The Swordholder

Cheng Xin’s recovery proceeded apace. The doctors told her that even if all ten seven-millimeter bullets in the gun had struck her, and even if her heart had been shattered, modern medicine was capable of reviving her and fixing her up good as new—though it would have been a different matter if her brain had been hit.

The police told her that the last murder case in the world had occurred twenty-eight years ago, and this city hadn’t had a murder case in almost forty years. The police were out of practice when it came to the prevention and detection of murder, and that was why Wade had almost succeeded. Another candidate for the Swordholder position had warned the police. But Wade’s competitor had presented no proof, only a suspicion of Wade’s intent based on a sensitivity that this era lacked. The police, dubious of the accusation, wasted a lot of time. Only after discovering that Wade had faked a call from AA did they take action.

Many people came to visit Cheng Xin at the hospital: officials from the government, the UN, and the Solar System Fleet; members of the public; and, of course, AA and her friends. By now, Cheng Xin could easily tell the sexes apart, and she was growing used to modern men’s completely feminized appearance, perceiving in them an elegance that the men of her era lacked. Still, they were not attractive to her.

The world no longer seemed so strange, and Cheng Xin yearned to know it better, but she was stuck in her hospital room.

One day, AA came and played a holographic movie for her. The movie, named A Fairy Tale of Yangtze, had won Best Picture at that year’s Oscars. It was based on a song composed in busuanzi verse form by the Song Dynasty poet Li Zhiyi:

The film was set in some unspecified ancient golden age, and told the story of a pair of lovers, one who lived at the source of the Yangtze, and the other at its mouth. The pair was kept apart for the entire film; they never got to see each other, not even in an imaginary scene. But their love was portrayed with utter sorrow and pathos. The cinematography was also wonderful: The elegance and refinement of the lower Yangtze Delta and the vigor and strength of the Tibetan Plateau contrasted and complemented each other, forming an intoxicating mix for Cheng Xin. The film lacked the heavy-handedness of the commercial films of her own era. Instead, the story flowed as naturally as the Yangtze itself, and absorbed Cheng Xin effortlessly.

I’m at one end of the River of Time, Cheng Xin thought, but the other end is now empty….

The movie stimulated Cheng Xin’s interest in the culture of her new era. Once she recovered enough to walk, AA brought her to art shows and concerts. Cheng Xin could clearly remember going to Factory 798[4] and the Shanghai Biennale to see strange pieces of contemporary “art,” and it was hard for her to imagine how much art had evolved in the three centuries she was asleep. But the paintings she saw at the art show were all realistic—beautiful colors enlivened with vitality and feeling. She felt each painting was like a heart, beating gently between the beauty of nature and human nature. As for the music, she thought everything she heard sounded like classical symphonies, reminding her of the Yangtze in the movie: imposing and forceful, but also calm and soothing. She stared at the flowing river until it seemed that the water had ceased moving, and it was she that was moving toward the source, a long, long way….

The art and culture of this age were nothing like what she had imagined, but it wasn’t simply a matter of a return to classical style, either. It was more of a spiraling sublimation of post-postmodernism, built upon a new aesthetic foundation. For instance, A Fairy Tale of Yangtze contained profound metaphors for the universe and space and time. But Cheng Xin was most impressed by the disappearance of the gloomy despair and bizarre noise so prevalent in the postmodern culture and art of the twenty-first century. In their place was an unprecedented warm serenity and optimism.

“I love your era,” said Cheng Xin. “I’m surprised.”

“You’d be even more surprised if you knew the artists behind these films, paintings, and music. They’re all Trisolarans from four light-years away.” AA laughed uproariously as she observed Cheng Xin’s stunned gape.

Excerpt from A Past Outside of Time Cultural Reflection

After the creation of deterrence, the World Academy of Sciences—an international organization at the same level as the UN—was founded to receive and digest the scientific and technical information transmitted to Earth from Trisolaris.

People first predicted that Trisolaris would only provide knowledge to Earth in sporadic, disconnected fragments after much pressure, and sprinkle deliberate falsehoods and misleading ideas into what little they chose to share, so the scientists of Earth would have to sift through them carefully for nuggets of truth. But Trisolaris defied those expectations. Within a brief period of time, they systematically transmitted an enormous amount of knowledge. The treasure trove mainly consisted of basic scientific information, including mathematics, physics, cosmology, molecular biology of Trisolaran life forms, and so on. Every subject was a complete system.

There was so much knowledge, in fact, that it completely overwhelmed the scientific community on Earth. Trisolaris then provided ongoing guidance for the study and absorption of this knowledge. For a while, the whole world resembled a giant university. After the sophons ended their interference with the particle accelerators, Earth scientists were able to experimentally verify the core ideas of Trisolaran physics, giving humanity confidence in the veracity of these revelations. The Trisolarans even complained multiple times that humanity was absorbing the new knowledge too slowly. The aliens seemed eager for Earth to catch up to Trisolaris in scientific understanding—at least in the basic sciences.

Faced with such a puzzling response, humans came up with multiple explanations. The most plausible theory posited that the Trisolarans understood the advantage of the accelerating pace of human scientific development and wanted to gain access to new knowledge through us. Earth was treated as a knowledge battery: After it was charged fully with Trisolaran knowledge, it would provide more power.

The Trisolarans explained their own actions this way: Their generous gift of knowledge was done out of respect for Earth civilization. They claimed that Trisolaris had received even more benefits from Earth. Human culture gave Trisolaris new eyes, allowed Trisolarans to see deeper meanings in life and civilization and appreciate the beauty of nature and human nature in ways they had not understood. Human culture was widely disseminated on Trisolaris, and was rapidly and profoundly transforming Trisolaran society, leading to multiple revolutions in half a century and changing the social structure and political system on Trisolaris to be more similar to Earth’s. Human values were accepted and respected in that distant world, and all Trisolarans were in love with human culture.

At the beginning, humans were skeptical of these claims, but the incredible wave of cultural reflection that followed seemed to prove them true.

After the tenth year of the Deterrence Era, besides additional scientific information, Trisolaris began to transmit cultural and artistic products done in imitation of human models: films, novels, poetry, music, paintings, and so on. Surprisingly, the imitations were not at all awkward or childish; right away, the Trisolarans produced sophisticated, high-quality art. Scholars called this phenomenon cultural reflection. Human civilization now possessed a mirror in the universe, through which humanity gained a new understanding of itself through a novel perspective. In the following ten years, Trisolaran reflection culture became popular on Earth, and began to displace the decadent native human culture that had lost its vitality. Reflection culture became the new source for scholars seeking new cultural and aesthetic ideas.

These days, without being explicitly told, it was very hard to tell if a film or novel was authored by a human or a Trisolaran. The characters in Trisolaran artistic creations were all human, and they were set on Earth, with no trace of alienness. This seemed a powerful confirmation of the acceptance of Earth culture by Trisolaris. At the same time, Trisolaris itself remained shrouded in mystery, with almost no details about the world itself being transmitted. The Trisolarans explained this by saying that their own crude native culture was not ready to be shown to humans. Given the vast gap in biology and natural environment between the two worlds, such displays might erect unexpected barriers in the valuable exchange that was already taking place.

Humanity was glad to see everything developing in a positive direction. A ray of sunlight lit up this corner of the dark forest.

Deterrence Era, Year 61 The Swordholder

On the day of Cheng Xin’s discharge, AA told her that Sophon wanted to meet her.

Cheng Xin understood that AA wasn’t referring to the subatomic particles endowed with intelligence sent by Trisolaris, but to a woman, a robot woman developed by the most advanced human AI and bionics technology. She was controlled by the sophons and acted as the Trisolaran ambassador to Earth. Her appearance facilitated a more natural interchange between the two worlds than having sophons manifest themselves by unfolding in lower dimensions.

Sophon lived on a giant tree at the edge of the city. Viewed from the flying car, the leaves on the tree were sparse, as though it were late autumn. Sophon lived on the branch at the top, where a single leaf hung, an elegant dwelling made of bamboo and surrounded by a white cloud. The day was cloudless, and it was clear that Sophon’s house generated the white mist.

Cheng Xin and AA walked along the branch until they reached the tip. The road was lined with smooth pebbles, and they saw lush lawns on both sides. They descended a spiraling staircase to reach the door of the house itself, where Sophon welcomed them. The gorgeous Japanese kimono on her petite figure resembled a layer of blooming flowers, but when Cheng Xin saw her face, the flowers seemed to lose color. Cheng Xin could not imagine a more perfect beauty, a beauty animated by a lively soul. She smiled, and it was as though a breeze stirred a pond in spring and the gentle sunlight broke into a thousand softly undulating fragments. Slowly, Sophon bowed to them, and Cheng Xin felt her entire figure illustrated the Chinese character 柔, or soft, in both shape and meaning.

“Welcome, welcome! I wanted to pay a visit to your honored abode, but then I wouldn’t be able to properly entertain you with the Way of Tea. Please accept my humble apologies. I am so delighted to see you.” Sophon bowed again. Her voice was as gentle and soft as her body, barely audible, but it possessed an irresistible charm, as if all other voices had to pause and step aside when she spoke.

The pair followed Sophon into the yard. The tiny white flowers in her bun quivered, and she turned around to smile at them from time to time. Cheng Xin had completely forgotten that she was an alien invader, that she was controlled by a powerful world four light-years away. All she saw was a lovely woman, distinguished by her overwhelming femininity, like a concentrated pigment pellet that could turn a whole lake pink.

Bamboo groves lined both sides of the trail through the yard. A white fog hung among the bamboo, which reached about waist-high and undulated. They crossed a little wooden bridge over a trickling spring, and Sophon stepped to the side, bowed, and showed them into the parlor. The parlor was decorated in a pure Eastern style, full of sunlight and wide openings in the four walls so that the space resembled a pavilion. They could see the blue sky and white clouds outside. The clouds were generated by the house itself and dissipated into tendrils. A small ukiyo-e Japanese woodblock print hung on the wall, along with a fan decorated with a Chinese-brush-painting landscape. The whole place exuded an air of simple elegance.

Sophon waited until Cheng Xin and AA were sitting cross-legged on the tatami mats, then sat herself down gracefully. Methodically, she laid out the implements for the tea ceremony in front of her.

“You’re going to have to be patient,” AA whispered in Cheng Xin’s ear. “It’ll be two hours before you get to drink any tea.”

Sophon retrieved a spotless white cloth from her kimono and began wiping the equally spotless implements. First, she carefully, slowly wiped each and every tea scoop, delicate spoons with long handles carved from single pieces of bamboo. Then she wiped each and every white porcelain and yellow copper tea bowl. With a bamboo ladle, she transferred the clear spring water from a ceramic container to a teapot and placed it above a refined copper brazier to boil. Then she scooped powdered green tea from the tea caddy into the tea bowls, brushing them with a bamboo tea whisk in a circular motion….

She performed each step in a deliberate, slow manner, even repeating some of the steps. Just wiping the tea ceremony implements took nearly twenty minutes. Clearly, Sophon executed these actions not for their results, but for their ceremonial significance.

But Cheng Xin didn’t feel bored. Sophon’s graceful, gentle movements had a hypnotic, mesmerizing effect on her. From time to time, a light breeze wafted through the room, and Sophon’s pale arms seemed to move not of their own accord, but to drift with the breeze. Her hands, smooth as jade, seemed to be caressing not implements for making tea, but something softer, lighter, more cloudlike… like time. Yes, she was caressing time. Time turned malleable and meandered slowly, like the fog that drifted through the bamboo groves. This was another time. Here, the history of blood and fire had disappeared, and the world of everyday concerns retreated somewhere far away. All that was left were clouds, the bamboo grove, and the fragrance of tea. They had achieved wa kei sei jaku—harmony, respect, purity, and tranquility, the four principles of the Way of Tea.

After an unknown amount of time, the tea was ready. Following another series of complicated ceremonial procedures, Sophon finally handed the bowls of tea to Cheng Xin and AA. Cheng Xin took a sip of the lush, green drink. A fragrant, bitter sensation suffused her body, and her mind seemed to clear.

“When all of us women are together, the world is so beautiful.” Sophon’s voice was still slow and mild, barely audible. “But our world is also very fragile. All of us women must take care to protect it.” Then she bowed deeply, and her voice grew excited. “Thank you for your care in advance! Thank you!”

Cheng Xin understood very well what was meant but not said, as well as the true significance of the tea ceremony.

The next meeting pulled Cheng Xin back into the complex reality around her.

The day after Cheng Xin visited Sophon, six Common Era men came to see her. These were the candidates competing to succeed Luo Ji in the Swordholder position. They were between thirty-four and sixty-eight years old. Compared to the beginning of the Deterrence Era, fewer Common Era individuals were emerging from hibernation, but they still formed a stratum of society on their own. All of them had some difficulty reintegrating into modern society. Most men from the Common Era tried to, consciously or otherwise, feminize their appearance and personality to adjust to the new feminine society. But the six men in front of Cheng Xin all stubbornly held on to their outdated masculine appearance and personality. If Cheng Xin had met them a few days ago, she would have found them comforting, but now, she felt only a sense of oppression.

She could see no sunlight in their eyes; their expressions appeared as masks that disguised their true feelings. Cheng Xin felt that she was facing a city wall built from six cold, hard rocks. The wall, roughened and toughened by the passing years, chilled her with its heaviness, and seemed to hint at death and bloodshed.

Cheng Xin first thanked the candidate who had warned the police. In this she was sincere—he had saved her life, after all. The forty-eight-year-old man was named Bi Yunfeng, and he had once been a designer for the world’s largest particle collider. Like Cheng Xin, he was sent as a liaison to the future in the hope that the particle collider would be restarted once humankind broke through the lock placed on them by the sophons. Unfortunately, none of the particle accelerators built during his time had survived to the Deterrence Era.

“I hope I haven’t made a mistake,” he said. Perhaps he was trying to be funny, but Cheng Xin and the others didn’t laugh.

“We’re here to persuade you to not compete for the Swordholder position.” Another man got right to the point. His name was Cao Bin, and he was thirty-four, the youngest of the candidates. At the start of the Trisolar Crisis, he had been a physicist, a colleague of the famous Ding Yi. After the truth of the sophons’ lock on fundamental research was revealed, he was disappointed by the thought that physics had turned into a mathematical game divorced from experimental basis, and entered hibernation to wait for the lock to be released.

“If I do declare my candidacy, do you think I will win?” asked Cheng Xin. She had been pondering this question nonstop since her return from Sophon’s home. She could barely sleep.

“If you do, it’s almost certain that you will win,” Ivan Antonov said. The handsome Russian was the next youngest of the candidates, at forty-three years old. He had an impressive résumé: Once the youngest vice-admiral in the Russian Navy, he later became the deputy commander of the Baltic Fleet. He had entered hibernation because of a terminal illness.

“Do I possess a lot of deterrent force?” asked Cheng Xin, smiling.

“You are not without qualifications. You once served in the PIA. During the last few centuries, that agency has actively gathered an enormous amount of intelligence about Trisolaris. Before the Doomsday Battle, it had even warned the human fleets about the imminent droplet attack, though the warning was ignored. Nowadays, the PIA is seen as a legendary organization, and this will give you points. In addition, you’re the only human to possess another world, which makes you able to save this world…. Never mind that the leap in logic is suspect; that’s how the public thinks—”

“Let me get to the point,” a bald man interrupted Antonov. He was named A. J. Hopkins—or at least that’s what he called himself. His identity had been completely lost by the time he emerged from hibernation, and he refused to divulge any information about himself, not even bothering to make it up. This made it difficult for him to become a citizen of the new world—though his mysterious past also helped make him a competitive candidate. He and Antonov were considered to possess the most deterrent force. “In the eyes of the public, the ideal Swordholder looks like this: He should terrify the Trisolarans without terrifying the people of Earth. Since such a combination cannot exist, the people will lean toward someone who doesn’t terrify them. You don’t frighten them because you’re a woman, and a woman who seems angelic in their eyes, at that. These sissies are more naïve than even the children of our time; all they can see are superficial qualities…. Look, they all think everything is developing wonderfully, and we are on the cusp of achieving universal peace and love. Deterrence is no longer so important, so they want someone with a gentler hand holding the sword.”

“Isn’t it true, though?” Cheng Xin asked. Hopkins’s contemptuous tone annoyed her.

The six men didn’t answer her, but they exchanged glances with each other. Their gazes now looked even darker and colder. Standing in their midst, Cheng Xin felt as if she were on the bottom of a well. She shivered.

“Child, you’re not suited to be the Swordholder.” At sixty-eight, the speaker was the oldest of the candidates. Before hibernation, he had been South Korea’s vice minister of foreign affairs. “You have no political experience, you are young, you lack the judgment to evaluate situations correctly, and you don’t possess the requisite psychological qualities to be the Swordholder. All you have is kindness and a sense of responsibility.”

The last candidate, an experienced attorney, now spoke up. “I don’t think you really want to be the Swordholder. You must know what kind of sacrifices are required.”

This last speech silenced Cheng Xin. She had just learned what Luo Ji had endured during the Deterrence Era.

After the six candidates departed, AA said to Cheng Xin, “I don’t think what the Swordholder goes through can be called living. It’s worse than being in hell. Why would these Common Era men want that?”

“To be able to determine the fate of all of humanity and another race with a single finger is very attractive to some men from that era. Some devote their entire lives to pursue such power. They become obsessed with it.”

“Um, are you obsessed, too?”

Cheng Xin said nothing. Things were no longer simple.

“It’s hard to imagine a man so dark, so crazy, so perverted.” AA meant Wade.

“He’s not the most dangerous.”

This was true. Wade did not hide his viciousness deeply. The layers and layers of disguises that people of the Common Era wore to hide their real intentions and feelings were unimaginable to AA and contemporary humans. Who knew what was hidden behind the cold, expressionless masks worn by the six men? Who knew whether one of them might be another Ye Wenjie or Zhang Beihai? More terrifyingly, whether all of them were?

The beautiful world revealed its fragility to Cheng Xin, like a lovely soap bubble floating through a bramble bush: A single touch was enough to destroy everything.

A week later, Cheng Xin came to the UN Headquarters to attend the handover ceremony for the two planets in the DX3906 system.

Afterwards, the PDC chair spoke with her. On behalf of the UN and the Solar System Fleet, he asked her to declare her candidacy for the Swordholder. He explained that there was uncertainty about the six existing candidates. For any of them to be elected would lead to mass panic, as a considerable portion of the population believed each of the candidates to be a tremendous danger and threat. The consequences of electing any of them were unpredictable. In addition, all of the candidates distrusted Trisolaris and exhibited aggressive tendencies toward it. If one of them were elected, the second Swordholder might collaborate with the hardliners on Earth and in Fleet International to impose harsher policies toward Trisolaris and demand more concessions from them. Such a move might terminate the developing peace and scientific and cultural exchange between the two worlds, leading to disaster….

But Cheng Xin could prevent all of this.

After humanity ended its second cave-dwelling stage, the UN Headquarters moved back to its old address. Cheng Xin was familiar with it: The exterior of the Secretariat Building looked the same as three centuries ago, and even the sculptures on the plaza in front were perfectly preserved, as was the lawn. Cheng Xin stood and recalled that tumultuous night 270 years ago: the announcement of the Wallfacer Project; Luo Ji’s shooting; the chaotic crowd under the swaying spotlights; her hair blowing about in the turbulence from the helicopters; the ambulance departing with flashing red lights and shrill sirens… everything was as clear as yesterday. Wade stood with his back against the lights of New York City, and uttered the line that had transformed her life: “We’ll send only a brain.”

Without that statement, everything that was happening now would have nothing to do with her. She would be a common woman and would have died more than two centuries ago. Everything about her would have disappeared without a trace upstream in time’s long river. If she had been fortunate, her tenth-generation descendants would now be waiting for the selection of the second Swordholder.

But she was alive. She faced the crowd on the plaza. A hologram of her image floated above them like a colorful cloud. A young mother came up to Cheng Xin and handed her baby, only a few months old, to her. The baby giggled at her, and she held him close, touching her face to his smooth baby cheeks. Her heart melted, and she felt as if she were holding a whole world, a new world as lovely and fragile as the baby in her arms.

“Look, she’s like Saint Mary, the mother of Jesus!” the young mother called out to the crowd. She turned back to Cheng Xin and put her hands together. Tears flowed from her eyes. “Oh, beautiful, kind Madonna, protect this world! Do not let those bloodthirsty and savage men destroy all the beauty here.”

The crowd cried out in joy. The baby in Cheng Xin’s arms, startled, began to cry. She held the baby tighter.

Do I have another choice?

The answer came to her, brooking no doubt.

No. None at all.

There were three reasons.

First, being declared a savior was just like being pushed under the guillotine: There was no choice involved. This had happened to Luo Ji, and now it was happening to her.

Second, the young mother and the soft, warm bundle in Cheng Xin’s arms made her realize something. She understood for the first time her own feelings toward this new world: maternal instinct. She had never experienced such a feeling during the Common Era. Subconsciously, she saw everyone in the new world as her child, and she could not bear to see them come to harm. Before, she had mistakenly thought of it as a sense of responsibility. But, no, maternal instinct was not subject to rationalization; she could not escape it.

The third fact stood in front of her like an unscalable wall. Even if the first two reasons did not exist, this wall would remain: Yun Tianming.

This situation was a hell, a bottomless abyss, the same as the abyss Yun Tianming had plunged into for her sake. She could not back off now. She had to accept karma. It was her turn.

Cheng Xin’s childhood had been full of her mother’s love, but only her mother’s love. She had asked her mother where her father was. Unlike some other single mothers, her mother responded calmly. She said she didn’t know, and then, after a sigh, added that she wished she did. Cheng Xin had also asked her where she had come from, and her mother had told her she was found.

This wasn’t a lie. Cheng Xin really had been found. Her mother had never married, but one night, while on a date with her boyfriend at the time, she saw a three-month-old baby abandoned on a park bench, along with a bottle of milk, a thousand yuan, and a slip of paper with the baby girl’s birthday. Her mother and the boyfriend had intended to bring the baby to the police, who would have turned the baby over to the city’s civil affairs department, who would have sent her to an orphanage.

Instead, her mother decided that she wanted to bring the baby home and go to the police in the morning. Perhaps it was the experience of being a mother for a night, or some other reason, but the next morning, she found that she couldn’t send the child away. Every time she thought of parting from the young life, her heart ached, and so she decided to become the child’s mother.

The boyfriend left her because of this. During the following decade, she dated four or five other men, but all of them ended up leaving her because of Cheng Xin. Later, Cheng Xin found out that none of the men had explicitly objected to her mother’s decision to keep her, but if any of them ever showed a trace of impatience or lack of understanding, her mother broke up with him. She refused to let any harm come to Cheng Xin.

When she was little, Cheng Xin never thought her family was incomplete. Instead, she thought it just the way it should be: a small world made up of mother and daughter. The small world possessed so much love and joy that she even suspected that adding a father would be extraneous. Later, she did miss having a father’s love—at first, only a vague sensation, but later a growing ache. And that was when her mother did find a father for her, a very kind man full of love and a sense of responsibility. He fell in love with Cheng Xin’s mother in large part because of how much she loved Cheng Xin. And so a second sun appeared in Cheng Xin’s life. She felt that her small world really was complete, and so her parents did not have another child.

Later, Cheng Xin left her parents to go to college. After that, her life was like a runaway horse that carried her farther and farther until, finally, not only did she have to part from them in space, but also time—she had to be sent to the future.

That night when she left her parents for the last time would be carved in her mind forever. She had lied to her parents and said that she’d be back the next day—she couldn’t bear to say good-bye, and so she had to leave without saying anything. But they seemed to know the truth.

Her mother had held her hand and said, “My darling, the three of us are together because of love….”

Cheng Xin spent that night standing in front of her parents’ window. In her mind, the night breeze and the twinkling stars and everything else repeated her mother’s last words.

Three centuries later, she was finally ready to do something for love.

“I will be a candidate for the Swordholder,” she said to the young mother.

Deterrence Era, Year 62 Gravity, in the Vicinity of the Oort Cloud

Gravity had been pursuing Blue Space for half a century.

It finally approached its target. Only three AU separated the hunter and the hunted. Compared to the 1.5 light-years that the two ships had traversed, this was mere inches.

A decade ago, Gravity had passed through the Oort Cloud. This region, about one light-year from the sun at the edge of the Solar System, was the birthplace of comets. Blue Space and Gravity were the first human spaceships to cross this border. The region didn’t feel anything like a cloud, though. Once in a while, a frozen ball of dirt and ice—a tailless comet—passed tens of thousands or hundreds of thousands of kilometers away, invisible to the naked eye.

Once Gravity left the Oort Cloud behind, the ship entered true outer space. From here, the sun appeared as just another star behind the ship. It lost its reality and became like an illusion. In every direction, all one could see was a bottomless abyss, and the only objects whose existence could be ascertained by the senses were the droplets flying in formation with Gravity. The droplets flanked the ship at a distance of about five kilometers, just visible to the naked eye. Those aboard Gravity liked to gaze at the droplets with telescopes as a source of comfort in the endless emptiness. Observing the droplets was, in a sense, just looking at themselves. The mirrorlike surface of the droplets reflected an image of Gravity. The dimensions were a bit distorted, but due to the perfect smoothness of the surface, the image was particularly clear. With sufficient magnification on their telescopes, the observers could even pick out the porthole, and themselves in it, in the reflection.

Most of the one hundred-plus officers and crew aboard Gravity didn’t experience this solitude because they had spent the majority of the past fifty years in hibernation. During routine cruising, only about five to ten crew members needed to be on duty. As the crew rotated through hibernation, each person was usually on duty for three to five years.

The entire pursuit was a complex game of acceleration between Gravity and Blue Space. First of all, Blue Space couldn’t just accelerate continuously, as doing so would cost it precious fuel and ultimately deprive it of mobility. Even if it managed to escape Gravity, it would be committing suicide in the endless empty desert of outer space if it exhausted its fuel. Although Gravity had more fuel onboard than Blue Space, it had constraints of its own. Since it needed to be prepared for a return voyage, its fuel reserves had to be divided into four equal parts: the acceleration away from the Solar System; the deceleration before its destination; the acceleration toward the Solar System; and the deceleration before arriving at the Earth. Thus, the portion available for acceleration during the pursuit amounted to only one-quarter of the fuel. Based on calculations of Blue Space’s previous maneuvers and intelligence gathered by the sophons, Gravity had an accurate idea of Blue Space’s fuel reserves, but the latter had no information about the former’s stores. Thus, in this game, Gravity knew all the cards held by Blue Space, while Blue Space struggled in ignorance. During pursuit, Gravity consistently maintained a speed higher than Blue Space, but neither ship approached their maximum velocities. Moreover, twenty-five years after the start of the chase, Blue Space stopped accelerating, perhaps because it had used up all the fuel it dared.

During the half century of the hunt, Gravity repeatedly hailed Blue Space, explaining that running was meaningless. Even if the crew of Blue Space somehow escaped the hunters from Earth, the droplets would catch up and destroy them. But if they returned to Earth, they would receive a fair trial. They had the option to greatly shorten the pursuit by surrendering. But Blue Space ignored these entreaties.

A year previously, when Gravity and Blue Space were thirty AU apart, something not entirely unexpected occurred: Gravity and the two accompanying droplets entered a region of space where the sophons lost their quantum ties to home, terminating real-time communications with Earth. Gravity had to communicate with Earth through only neutrinos and radio. Transmissions from Gravity now took a year and three months to reach the Earth, and the ship had to wait an equally long time to receive a reply.

Excerpt from A Past Outside of Time More Indirect Evidence for the Dark Forest: Sophon-Blind Regions

Near the beginning of the Crisis Era, as Trisolaris sent sophons toward the Earth, it also launched six sophons at near-lightspeed to explore other regions of the galaxy.

All of these sophons soon entered blind regions and lost contact with home. The longest-lasting one managed to get seven light-years away. Additional sophons launched later met with the same fate. The closest blind region, only about 1.3 light-years from Earth, was the one encountered by the sophons that accompanied Gravity.

Once the quantum entanglement between sophons was broken, it could not be restored. Any sophon entering a blind region was lost forever.

Trisolaris remained mystified by the kind of interference the sophons received: Perhaps it was a natural phenomenon, or perhaps it was “man”-made. Scientists from both Trisolaris and Earth leaned toward the latter explanation.

Before being blinded, the sophons were able to explore only two nearby stars with planets. Neither system exhibited signs of life or civilization. But Earth and Trisolaris both came to the conclusion that their desolation was precisely why the sophons were allowed to approach.

Thus, even deep into the Deterrence Era, the universe at large remained hidden from the two worlds by a mysterious veil. The existence of these blind regions seemed to provide indirect proof for the dark forest nature of the universe: Something was preventing the cosmos from becoming transparent.

Deterrence Era, Year 62 Gravity, in the Vicinity of the Oort Cloud

Losing the sophons was not fatal to Gravity’s mission, though it did make the job much harder. Before, the sophons could enter Blue Space at will and report on everything that was going on; now Blue Space appeared to Gravity as a sealed box. Moreover, the droplets lost real-time communications with Trisolaris and had to rely on the onboard AI. This led to unpredictable results.

The captain of Gravity decided that he could no longer afford to wait. He ordered Gravity to accelerate further.

As Gravity approached, Blue Space hailed the hunters for the first time, proposing a plan: Blue Space would load two-thirds of the crew—including the main suspects—onto pinnaces and send the pinnaces to Gravity if the remainder of the crew was allowed to continue their voyage into deep space aboard Blue Space. This way, a vanguard and seed for the human race would be preserved in space, keeping alive the hope for further exploration.

Gravity vehemently denied this request. The entire crew of Blue Space was suspected of murder, and all had to be tried. Space had transformed them until they were no longer members of the human race. Under no circumstances could they be allowed to “represent” humanity in space exploration.

Blue Space apparently realized the futility of running and of resisting. If only a human spaceship pursued them, then they at least stood a chance if they fought. But the two droplets changed the strategic calculus. Before them, Blue Space was nothing but a paper target, and there was no chance of escape. When the two ships were only fifteen AU apart, Blue Space announced its surrender and began to decelerate at maximum power. The distance between the two ships shrank rapidly, and it seemed that the long hunt was at last coming to an end.

Gravity’s crew emerged from hibernation and readied the ship for combat. The vessel, once silent and deserted, was once again filled with people.

Those who had been awakened faced the prospect of both a target nearly at hand and the loss of real-time communications with Earth. This loss did not pull them spiritually closer to the crew of Blue Space. To the contrary, like a child who was separated from her parents, the crew distrusted the parentless wild children even more. Everyone wished to capture Blue Space as quickly as possible and return home. Even though both crews were in the cold vastness of space, voyaging in the same direction at approximately the same speed, the natures of their voyages were completely different. Gravity had a spiritual anchor, while Blue Space was adrift.

In the ninety-eighth hour after the crew’s emergence from hibernation, Dr. West, Gravity’s psychiatrist, received his first patient. This visit from Commander Devon surprised the doctor. According to his records, Devon had the highest stability score of anyone aboard. Devon was in charge of the military police aboard Gravity, and it would be his responsibility to disarm Blue Space and arrest the crew once it was caught. Gravity’s male crew members belonged to the last generation from Earth who still looked masculine, and Devon had the most masculine appearance among them. He was sometimes even mistaken for a Common Era man. He had often spoken out in favor of taking a hard line toward the suspects, suggesting that the death penalty ought to be revived.

“Doctor, I know that you’ll keep my confidence,” Devon said carefully. His tone was in marked contrast to his usual hard-edged style. “I know that what I’m about to say will sound funny.”

“Commander, in my professional capacity, I wouldn’t laugh at anyone.”

“Yesterday, at approximately stellar time 436950, I left Conference Room Four and followed Passageway Seventeen back to my cabin. As I approached the Intelligence Center, a sublieutenant came toward me—or, at least, a man dressed in the uniform of a Space Force sublieutenant. At that time, except for crew members on duty, everyone should have been asleep. But I didn’t think it was so strange to meet someone in the passageway. Except…” Devon shook his head and his eyes lost focus, as though trying to recall a dream.

“What was wrong?”

“The man and I passed by each other. He saluted me, and I glanced at him….”

Devon stopped again, and the doctor nodded for him to continue.

“He was… he was the commander of the marines from Blue Space, Lieutenant Commander Park Ui-gun.”

“You mean Blue Space, our prey?” West’s tone was calm, betraying no hint of surprise.

Devon didn’t answer the question. “Doctor, you know that as part of my duties, I’ve been monitoring the interior of Blue Space through the real-time images transmitted by the sophons. I know the crew of that ship better than I know the crew here. I know what Lieutenant Commander Park Ui-gun looks like.”

“Maybe it was someone from our ship who looks like him.”

“No, there’s no one—I know everyone onboard. Also… after the salute, he passed by me without any expression. I stood there, stunned. But by the time I turned around, the passageway was empty.”

“When did you wake up from hibernation?”

“Three years ago. I needed to keep an eye on the activities onboard our target. Before that, I was also among those aboard who had stayed out of hibernation the longest.”

“Then you must have experienced the moment when we entered the sophons’ blind region.”

“Of course.”

“Before that, you spent so much of your time watching those aboard Blue Space that I think you probably felt as though you were on Blue Space rather than Gravity.”

“Yes, Doctor. I did often feel that way.”

“And then, the surveillance images were cut off. You couldn’t see anything over there anymore. And you were tired…. Commander, it’s simple. Trust me: This is normal. I suggest you get more rest. We have plenty of people now to do the work that needs to be done.”

“Doctor, I’m a survivor of the Doomsday Battle. After my ship exploded, I was curled up in a life pod the size of your desk, drifting in the vicinity of Neptune’s orbit. By the time I was rescued, I was close to death, but my mind was still sound, and I never suffered any delusions…. I believe what I saw.” Devon got up and walked away. He turned around at the cabin door. “If I meet that bastard again—doesn’t matter where—I’m going to kill him.”

Some time after that, an accident happened in Ecological Area #3—a nutrient tube ruptured. The tube was made of carbon fiber, and as it wasn’t subject to pressure, the probability of a malfunction was very low. Ecological Engineer Ivantsov passed through the aeroponically grown plants, as dense as a rainforest, and saw that others had already shut off the valve leading to the ruptured tube and were cleaning up the yellow nutrient broth.

Ivantsov stopped dead when he saw the ruptured tube.

“This… is caused by a micrometeoroid!”

Someone laughed. Ivantsov was an experienced and prudent engineer, and that made his outburst even funnier. All the ecological areas were buried in the center of the ship. Ecological Area #3 was tens of meters away from the nearest section of the exterior hull.

“I worked more than a decade in external maintenance and I know what a micrometeoroid strike looks like! Look, you can see the typical signs of high-temperature ablation around the edges of the rupture.”

Ivantsov closely examined the inside of the tube; then he asked a technician to cut off a ring of material around the rupture and magnify it. The chatter died down as everyone stared at the 1000x image. There were tiny black particles, a few microns in diameter, embedded in the wall of the tube. The particles twinkled like unfriendly eyes in the magnified image. They all knew what they were looking at. The meteoroid must have been about one hundred microns in diameter. It had shattered as it went through the tube, its broken pieces winding up embedded in the wall opposite the breach.

As one, they looked up.

The ceiling above the ruptured tube looked smooth and undamaged. Furthermore, above the ceiling, tens, maybe hundreds more bulkheads of various thicknesses separated this place from space. An impact-breach in any of these bulkheads would have triggered a high-level alert.

But the micrometeoroid had to have come from space. Based on the condition of the rupture, the micrometeoroid had struck the tube at a relative velocity of thirty thousand meters per second. It would have been impossible to accelerate the projectile to such speed from within the ship, much less from within the ecological area.

“It’s like a ghost,” a sublieutenant named Ike muttered, and left. His choice of words was meaningful: About ten hours earlier, he had seen another, bigger ghost.

Ike had been trying to fall asleep in his cabin when he saw a round opening appear in the wall opposite his bed. It was about a meter across, and occupied the space where a Hawaiian landscape had hung. It was true that many of the bulkheads on the ship could shift and transform so that doors could appear anywhere, but a circular opening like this was impossible. Moreover, the cabin walls of mid-level officers were made of metal and could not deform this way. A closer examination by Ike revealed that the edge of the opening was perfectly smooth and reflective, like a mirror.

Although the hole was strange, Ike was rather pleased by it. Sublieutenant Vera lived next door.

Verenskaya was the AI system engineer aboard Gravity. Ike had been trying to get the Russian beauty to go out with him, but she hadn’t shown any interest. Ike still remembered his latest attempt two days ago.

He and Verenskaya had just gotten off duty. As usual, they walked back to the officers’ quarters together, and as they reached Verenskaya’s cabin, Ike tried to invite himself in. Verenskaya blocked her door.

“Come on, sweetheart,” Ike said. “Let me in for a visit. It’s not very neighborly to never invite me over. They’ll think I’m not a real man.”

Verenskaya looked askance at Ike. “Any real men on this ship would be too worried about our mission to think about getting into the pants of every woman around them.”

“What’s there to worry? After we catch those murderers, there will be no more danger. Happy times will be here!”

“They’re not murderers! Without deterrence, Blue Space would be humankind’s only hope. Yet we’re now hunting them down, allied with the enemies of the human race. Don’t you feel ashamed?”

“Um… baby, if you feel this way… how did you…”

“How did I get to join this mission? Is that what you want to say? Why don’t you go to the psychiatrist and the captain to report me? They’ll put me in forced hibernation and kick me out of the fleet after we return. That’s just my wish!” Verenskaya slammed the door in his face.

However, now Ike had a perfect excuse to enter Verenskaya’s cabin. He unbuckled his weightlessness belt and sat up in his bed, but stopped when he saw that the bottom half of the round opening made the top of the cabinet against the wall disappear as well. The edge of what remained of the cabinet was also perfectly smooth and reflective, like the edge of the opening itself. It was as if some invisible knife had cut through the cabinet and everything inside, including the stacks of folded clothes. The mirrorlike surface of the cross-section ran up against the edge of the round opening, and the whole reflective surface looked like a portion of the inside of a sphere.

Ike pushed against the bed and lifted off in the weightlessness. Looking through the opening, he almost screamed in fright. This must be a nightmare!

Through the hole, he could see that a part of Verenskaya’s bed, pushed up against the cabin wall, had also disappeared. Verenskaya’s lower legs had been cut off. Although the cross section of the bed and the legs were also smooth and reflective, as though covered by a layer of mercury, he could see Verenskaya’s muscles and bones through it. But Verenskaya seemed all right. She was still in deep sleep, and her firm breasts slowly moved up and down as she breathed. Normally, Ike would have admired such a sight, but right now he only felt a supernatural fright. When he calmed down and looked closer, he saw that the cross-section of Verenskaya’s legs and bed also formed a spherical surface that matched the round opening.

He was looking at a bubble-shaped space about a meter in diameter, which erased everything within its path.

Ike picked up a violin bow from the nightstand, and, with a trembling hand, poked it into the bubble. The part of the bow extended inside the bubble disappeared, but the bow hair remained taut. He pulled the bow back and saw that it was undamaged. But he was still glad that he hadn’t tried to go through the hole—who knew if he would emerge from the other side unharmed?

Ike forced himself to be calm and tried to think of the most rational explanation for the eerie sight. Then he made what he thought was a wise decision: He put on his sleep cap and lay back down on the bed. He buckled his weightlessness belt back on and set the sleep cap for half an hour.

He woke up after half an hour, and the bubble was still there.

So he set the sleep cap for an hour. When he woke up this time, the bubble and the hole in the wall were gone. The Hawaiian landscape was back on the wall and everything was as it was before the incident.

But Ike was worried about Verenskaya. He dashed out of his cabin and stopped in front of Verenskaya’s door. Instead of ringing the doorbell, he pounded on the door. His mind was filled with the terrifying vision of Verenskaya, close to death, lying on the bed with her legs cut off.

It took a while before the door opened, and a not-completely-awake Verenskaya demanded to know what he wanted.

“I came to see if you are… all right.” Ike’s gaze shifted down, and he saw that Verenskaya’s beautiful legs were perfect below the hem of her nightgown.

“Idiot!” Verenskaya slammed the door shut.

After returning to his cabin, Ike put his sleep cap on and set it for eight hours. As for what he had seen, the only wise thing to do was to shut up and say nothing. Due to Gravity’s special mission, the crew’s psychological state—especially that of the officers—was subject to constant monitoring. There was a special psychological monitoring corps aboard, comprising more than a dozen crew members out of the full complement of just over a hundred. Some crew members had wondered whether Gravity was a stellar ship or a psychiatric hospital. And then there was also the annoying civilian psychiatrist West, who thought of everything in terms of mental disorders and illnesses and blockages, until one could come to the conclusion that he would subject a clogged toilet to psychiatric analysis. The mental screening process onboard Gravity was extremely strict, and even slight mental disorders would result in the sufferer being forced into hibernation. Ike was terrified of missing the upcoming historical encounter between the two ships. If that happened, when the ship returned to Earth in half a century, the girls back home would not see him as a hero.

But Ike did feel a slight diminution in his dislike for the psych corps and Dr. West. He had always thought of them as making mountains out of molehills, but he had never imagined that people could suffer such realistic delusions.

Compared to Ike’s minor delusion, Petty Officer Liu Xiaoming’s supernatural encounter would be considered quite spectacular.

Liu was performing a routine exterior hull inspection. This involved piloting a small pinnace at a certain distance from Gravity and examining the hull for any abnormalities, such as evidence of meteor strikes. This was an ancient, outdated practice no longer strictly necessary and rarely performed. The ship was full of sensors that monitored the hull continuously; any problems would be detected right away. Also, the operation could only be done when Gravity was coasting instead of accelerating or decelerating. As the ship approached Blue Space, frequent acceleration and deceleration was necessary for adjustments. This was one of those rare windows when the ship was coasting again, and Petty Officer Liu was ordered to take advantage of the opportunity.

Liu piloted the pinnace out of the bay in the middle of the ship and smoothly glided away from Gravity until he was at a distance where he could see the whole ship. The giant hull was bathed in the light from the galaxy. Unlike when most of the crew was in hibernation, light spilled from all the portholes, making Gravity seem even more magnificent.

But Liu noticed something incredible: Gravity was shaped like a perfect cylinder, however, right now, its tail ended in an inclined plane! The ship was also much shorter than it should be—about 20 percent shorter, to be exact. A giant, invisible knife had cut off Gravity’s tail.

Liu shut his eyes, then opened them a few seconds later. The tail was still missing. He felt chilled to the bone. The giant ship before him was an organic whole. If the tail were suddenly gone, the power distribution systems would suffer a catastrophic failure, and the ship would shortly explode. But nothing of the sort was happening. The ship cruised along without trouble, as though suspended in space. No alerts of any kind came from his earpiece or were shown on his screens.

He pressed the switch for the intercom and got ready to give a report, but shut off the channel before saying anything. He recalled the words of an old spacer who had been at the Doomsday Battle: “Your intuition is unreliable in space. If you must act based on intuition, count from one to one hundred first. At least count from one to ten.”

He closed his eyes and began to count. When he got to ten, he opened his eyes. The tail was still missing. He closed his eyes and continued to count, his breath coming faster now, but he struggled to remember his training, and forced himself to calm down. He opened his eyes when he reached thirty, and this time he saw the complete Gravity. He closed his eyes again, sighed, and waited until his heartbeat slowed down.

He piloted the pinnace to the stern of the ship, where he could see the three giant nozzles of the fusion drive. The engine wasn’t on, and the fusion reactor was kept at minimal power so that the nozzles only showed a faint red glow, reminding him of the clouds back on Earth at dusk.

Petty Officer Liu was glad that he hadn’t made a report. An officer might get therapy, but an NCO like himself would be forced into hibernation. Like Ike, Liu Xiaoming didn’t want to return to Earth a useless man.

Dr. West went to find Guan Yifan, a civilian scholar who worked in the observatory at the stern. Guan had a midship cabin assigned to him as living quarters, but he rarely went there. Most of the time, he remained in the observatory and asked the service robots to bring his meals. The crew referred to him as “the hermit at the stern.”

The observatory was a tiny spherical cabin where Guan lived and worked. His appearance was disheveled, with an unshaven face and long hair, but he still looked relatively youthful. When West saw Guan, he was floating in the middle of the cabin, looking restless: sweaty forehead, anxious eyes, his hand pulling at his collar as if he was unable to catch his breath.

“I already told you on the phone: I’m working and don’t have time for a visit.”

“It’s precisely because your call betrayed signs of mental disorder that I came to see you.”

“I’m not a member of the space force. As long as I’m no danger to the ship or the crew, you have no power over me.”

“Fine. I’ll leave.” West turned around. “I just don’t believe that someone with claustrophobia can work in here without trouble.”

Guan called out for West to stop, but West ignored him. As he expected, Guan chased after him and stopped him. “How did you know that? I am indeed… claustrophobic. I feel like I’m being packed into a narrow tube, or sometimes squeezed between two iron plates until I’m flat as a sheet….”

“Not surprising. Look at where you are.” The doctor indicated the cabin—it resembled a tiny egg nestled in a nest of crisscrossing cables and pipes. “You research phenomena at the largest scale, but you stay in the smallest space. And how long have you been here? It’s been four years since your last hibernation, hasn’t it?”

“I’m not complaining. Gravity’s mission is bringing fugitives to justice, not scientific exploration. I’m grateful to have this space at all…. Look, my claustrophobia has nothing to do with this.”

“Why don’t we take a walk on Plaza One? It will help.”

The doctor pulled Guan Yifan along, and the two drifted toward the bow of the ship. If the ship were accelerating, going from the stern of the ship to the bow would be equivalent to climbing up a one-kilometer well, but in the weightlessness of coasting, the trip was a lot easier. Plaza #1 was located at the bow of the cylindrical ship, under a semispherical, transparent dome. Standing there was like standing in space itself. Compared to the holographic projections of the star field on the walls of spherical cabins, this place induced an even stronger sense of the “desubstantiation effect.”

“Desubstantiation effect” was a concept from astronautic psychology. Humans on Earth were surrounded by objects, and the image of the world in their subconscious was thus material and substantial. But in deep space, away from the Solar System, the stars were only distant points of light and the galaxy was nothing more than a luminous mist. To the senses and the mind, the world lost its materiality, and empty space dominated. A space voyager’s subconscious image of the world thus became desubstantiated. This mental model was the baseline in astronautic psychology. Mentally, the ship became the only material entity in the universe. At sub-light speeds, the motion of the ship was undetectable, and the universe turned into one boundless, empty exhibition hall. Here, the stars were illusions, and the ship was the only object on display. This mental model brought with it a profound sense of loneliness, and it could cause the voyager to have subconscious delusions of being a “superobserver” toward the lone “object on display.” This feeling of being completely exposed could lead to passivity and anxiety.

Thus, many of the negative psychological effects of deep-space flight were due to the extreme openness of the external environment. In West’s extensive professional experience, it was extremely rare to develop claustrophobia the way Guan Yifan did. Even stranger to West was the fact that Guan did not seem relieved by the vast, open sky of Plaza #1; the restlessness caused by claustrophobia seemed to abate not one whit. This tended to support Guan’s assertion that his claustrophobia had nothing to do with the narrow confines of his observatory. West grew even more interested in his case.

“Don’t you feel better?”

“No, not at all. I feel trapped. Here, everything is so… enclosed.”

Guan glanced at the starry sky and then focused his gaze in the direction Gravity was heading. The doctor knew he was looking for Blue Space. The two ships were now only one hundred thousand kilometers apart, and coasting at approximately the same speed. At the scale of deep space, the two ships were practically flying in close formation. The leadership of both ships was in the process of negotiating the technical details of their docking. But Blue Space was still too far away to be seen with the naked eye. The droplets were invisible as well. Based on the agreement made with Trisolaris half a century ago, the droplets had shifted to a position about three hundred thousand kilometers from both Gravity and Blue Space. The two ships and the droplets formed a narrow isosceles triangle.

Guan Yifan turned his gaze back to West. “Last night, I had a dream. I went somewhere, somewhere really open, open in a way that you can’t even imagine. After I woke up, reality felt very enclosed and narrow, and that was how I came to be claustrophobic. It’s like… if, as soon as you were born, you were locked inside a small box, you wouldn’t care because that was all you’ve known. But once you’ve been let out and they put you back in, it feels completely different.”

“Tell me more about this place in your dream.”

Guan gave the doctor a mysterious smile. “I will describe it to the other scientists on the ship, maybe even the scientists on Blue Space. But I won’t tell you. I don’t have anything against you, Doctor, but I can’t stand the attitude shared by everyone in your profession: If you think someone has a mental disorder, you treat everything he says as merely the delusion of a diseased mind.”

“But you just told me it was a dream.”

Guan shook his head, struggling to remember. “I don’t know if it was a dream; I don’t know if I was awake. Sometimes, you can think you’re waking from a dream, only to find yourself still dreaming; other times, you’re awake, but it seems like you’re dreaming.”

“The second situation is extremely rare. If you experienced that, then it was almost certainly a symptom of some mental disorder. Oh, sorry, now you’re unhappy with me again.”

“No, no. I think we’re actually very similar. We both have our targets of observation. You observe the deranged, and I observe the universe. Like you, I also have some criteria for evaluating whether the observed objects are sound: harmony and beauty, in the mathematical sense.”

“Of course the objects you observe are sound.”

“But you’re wrong, Doctor.” Guan pointed at the glowing Milky Way, but his gaze remained on West, as though showing him some monster that had suddenly appeared out of nowhere. “Out there is a patient who may be mentally sound, but whose body suffers from paraplegia!”

“Why?”

Guan curled up and hugged his knees. The movement caused his body to slowly rotate in place. The magnificent Milky Way revolved around him, and he saw himself as the center of the universe.

“Because of the speed of light. The known universe is about sixteen billion light-years across, and it’s still expanding. But the speed of light is only three hundred thousand kilometers per second, a snail’s pace. This means that light can never go from one end of the universe to the other. Since nothing can move faster than the speed of light, it follows that no information and motive force can go from one end of the universe to the other. If the universe were a person, his neural signals couldn’t cover his entire body; his brain would not know of the existence of his limbs, and his limbs would not know of the existence of the brain. Isn’t that paraplegia? The image in my mind is even worse: The universe is but a corpse puffing up.”

“Interesting, Dr. Guan, very interesting!”

“Other than the speed of light, three hundred thousand kilometers per second, there’s another three-based symptom.”

“What do you mean?”

“The three dimensions. In string theory, excepting time, the universe has ten dimensions. But only three are accessible at the macroscopic scale, and those three form our world. All the others are folded up in the quantum realm.”

“I think string theory provides an explanation.”

“Some think that it is only when two strings encounter each other and some qualities are canceled out that the dimensions are unfolded into the macroscopic, and dimensions above three will never have such chances for encountering each other…. I don’t think much of this explanation. It is not mathematically beautiful. Like I said, this is the universe’s three and three hundred thousand syndrome.”

“What do you propose as the cause?”

Guan laughed uproariously and put his arm around the doctor’s shoulders. “Great question! I don’t think anyone has thought this far. I’m sure there’s a root cause, and it might be the most horrifying truth that science is capable of revealing. But… Doctor, who do you think I am? I’m nothing more than a tiny observer curled up in the tail of a spaceship, and only an assistant researcher at that.” He released West’s shoulders, and, facing the galaxy, let out a long sigh. “I’ve been in hibernation the longest of anyone aboard. When we left Earth, I was only twenty-six, and even now I’m only thirty-one. But in my eyes, the universe has already transformed from a source of beauty and faith into a bloating corpse. I feel old. The stars no longer hold any attraction for me. I want to go home.”

Unlike Guan Yifan, West had been awake for much of the voyage. He always believed that to maintain the mental health of others, he needed to keep his own emotions under control. But something seemed to buffet his heart now, and as he reviewed his own half century of travels, his eyes moistened. “My friend, I’m old, too.”

As if in response to their conversation, the battle alert klaxons blared, sounding like the entire sky full of stars was screaming. Warning information scrolled on floating windows that appeared above the plaza. The overlapping windows sprang up one after another and quickly covered the Milky Way like colorful clouds.

“Droplet attack!” West said to the confused Guan Yifan. “They’re both accelerating. One is headed for Blue Space, the other for us!”

Guan looked around, instinctively searching for something to grab on to in case the ship accelerated. But there was nothing around. In the end, he held on to the doctor.

West held his hands. “There won’t be enough time for any evasive maneuvers. We have only a few seconds left.”

After a brief panic, both felt an unexpected sense of relief. They were glad that death would arrive so quickly that there wasn’t even time to be terrified. Perhaps their discussion about the universe was the best preparation for death.

They both thought of the same thing, but Guan spoke it aloud first. “Looks like neither of us needs to worry about our patients anymore.”

Deterrence Era, Year 62 November 28, 4:00 P.M. to 4:17 P.M.: Deterrence Center

The high-speed elevator continued to descend, and the increasing layers of earth above seemed to put all their weight on Cheng Xin’s heart.

Half a year ago, a joint session of the UN and the Solar System Fleet had elected Cheng Xin to succeed Luo Ji as the Swordholder and given her authority to control the gravitational wave deterrence system. She had received almost twice as many votes as the next candidate. She was now proceeding to the Deterrence Center in the Gobi Desert, where the deterrence authority handover ceremony was to take place.

The Deterrence Center was the deepest man-made structure ever, about forty-five kilometers beneath the surface. This location was already below the crust, past the Mohorovičić discontinuity, in the mantle of the Earth. The pressure and temperature here were both far higher than in the crust, and the stratum around her was made up mostly of solid, hard peridotite.

The elevator took almost twenty minutes to reach its terminus. Cheng Xin stepped out of the elevator and saw a black steel door. White text on the door gave the formal name for the Deterrence Center: Gravitational Wave Universal Broadcast System Control Station Zero. The insignias of the UN and the Solar System Fleet were embossed on the door.

This ultra-deep structure was quite complex. It possessed its own independent air circulation system and was not directly connected with the atmosphere above the surface—otherwise, the high air pressure generated by a depth of forty-five kilometers would cause great discomfort to the occupant. It was also equipped with a powerful cooling system to withstand the high temperature of the mantle, nearly five hundred degrees Celsius.

All Cheng Xin could see, however, was emptiness. The lobby’s walls could all apparently act as electronic displays, but they showed nothing but whiteness, as though the building wasn’t in use yet. Half a century ago, when the Deterrence Center was designed, Luo Ji had been consulted, but he had only provided one piece of input:

As simple as a tomb.

The handover ceremony was a solemn occasion, but the bulk of it had been held on the surface forty-five kilometers above. There, all the leaders of Earth International and Fleet International, representing all of humanity, had gathered, and they watched as Cheng Xin entered the elevator. Only two people would oversee the final handover: the PDC chair and the chief of staff for the Solar System Fleet, representing the two institutions directly operating the deterrence system.

The PDC chair pointed at the empty lobby and explained to Cheng Xin that they would redecorate the place based on her ideas. If she wanted, she could have a lawn, plants, a fountain, and so forth. She could also choose to have a holographic simulation of scenes from the surface.

“We don’t want you to live like him,” said the chief of staff. Perhaps because of his military uniform, Cheng Xin saw in him traces of men of the past, and his words warmed her slightly. But the heavy weight on her heart, as heavy as the forty-five kilometers of earth above her, did not lessen.

Excerpt from A Past Outside of Time The Choice of the Swordholder: Ten Minutes Between Existence and Annihilation

The first dark forest deterrence system consisted of more than three thousand nuclear bombs wrapped in an oil film substance deployed in orbit around the sun. After detonation, the film would cause the sun to flicker and broadcast the location of Trisolaris to the universe. Although the system was grand, it was extremely unstable. After the droplets stopped blockading electromagnetic radiation from the sun, a transmission system based on using the sun as a superantenna was immediately put in place to supplement the nuclear bomb deterrence system.

Both of these systems relied on electromagnetic radiation, including visible light, as the broadcast medium. We now know that this is the most primitive technique for interstellar communication, equivalent to smoke signals in space. Since electromagnetic waves decay and become distorted rapidly, the broadcast range is limited.

At the time of the founding of deterrence, humankind already had a basic grasp of the technology for detecting gravitational waves and neutrinos, but they lacked the ability to modulate and transmit. These were the very first technologies humans demanded from Trisolaris. Compared to quantum communications, these technologies were still primitive, since both gravitational waves and neutrinos were limited by the speed of light, but they were a whole level above electromagnetic waves.

Both of these means of transmission decayed relatively slowly and had very long broadcast ranges. Neutrinos, in particular, interacted with almost nothing else. Theoretically, a modulated beam of neutrinos could transmit information to the other end of the universe, and the accompanying decay and distortion would not affect the decoding of the information. But while neutrinos must be focused in a particular direction, gravitational waves were omnidirectional, thus gravitational waves became the main method of establishing dark forest deterrence.

The fundamental principle of gravitational wave transmission relied on the vibration of a long string of extremely dense matter. The ideal transmission antenna would involve a large number of black holes connected together to form a chain that generated gravitational waves as it vibrated. But even Trisolaris didn’t possess such a level of technology, and humankind had to resort to constructing the vibrating string out of degenerate matter. The extremely dense degenerate matter packed an enormous mass into strings mere nanometers in diameter. A single string took up only a minuscule portion of the giant antenna, the bulk of which consisted of support and protection for the ultra-dense string. Thus, the total mass of the antenna wasn’t extraordinarily large.

The degenerate matter forming the vibrating string was naturally found in white dwarves and neutron stars. Under typical conditions, this substance naturally decayed and turned into regular matter over time. Man-made vibrating strings typically had a half-life of around fifty years, beyond which the antennas lost their effectiveness. Thus, every half century, the antennas needed to be refreshed with new ones.

During the earliest stage of gravitational wave deterrence, the main strategic concern was with ensuring deterrence power. Plans were made to build a hundred broadcasting stations scattered around the continents. But gravitational wave communication suffered from a flaw: The transmission equipment could not be miniaturized. The complex, gigantic antennas were extremely costly to manufacture, and in the end only twenty-three gravitational transmitters were built. But the focus on ensuring deterrence finally faded, due to another event.

During the Deterrence Era, the ETO gradually disappeared, but another kind of extremist organization sprang up. They believed in the cause of human supremacy, and advocated for the complete annihilation of Trisolaris. The “Sons of the Earth” was one of the largest of these organizations. In Year 6 of the Deterrence Era, more than three hundred “Sons of the Earth” attacked a gravitational wave broadcasting station located on Antarctica with the aim of seizing the transmitter. Equipped with advanced weapons such as mini-infrasonic nuclear bombs, and aided by members who had infiltrated the broadcasting station ahead of time, the attackers nearly succeeded. If the defending troops stationed at the site hadn’t destroyed the antenna in time, the consequences would have been disastrous.

This incident terrified both worlds. People began to realize the great danger posed by gravitational wave transmitters. Simultaneously, Trisolaris pressured Earth until gravitational wave transmission technology was strictly controlled, and the twenty-three broadcasting stations were cut down to four. Three of the stations were terrestrial, located in Asia, North America, and Europe, and the last one was the spaceship Gravity.

All the transmitters relied on an active trigger, because the dead hand trigger technique used in the circumsolar nuclear bomb system was no longer necessary. Luo Ji had established deterrence by himself, but now, if the Swordholder were killed, others would be able to take over.

Initially, the gigantic gravitational wave antennas had to be built on the surface. As technology advanced, in Year 12 of the Deterrence Era, the three terrestrial antennas and their support systems moved deep underground. Everyone understood, however, that burying the transmitters and the control center beneath the Earth’s surface primarily guarded against a threat originating from humankind itself, but was meaningless against an attack by Trisolaris. For droplets constructed from strong-interaction material, tens of kilometers of rock were not much different from mere liquid, barely able to impede their progress.

After Earth established deterrence, the Trisolar invasion fleet veered away, as verified through observation. With that threat diminished, most people turned their focus to the whereabouts of the ten droplets that had already reached the Solar System. Trisolaris insisted that four of the droplets remain in the Solar System, justifying the decision by arguing that the gravitational wave transmitters could be seized by extremist factions within humankind, and Trisolaris should have the power to take steps to protect both worlds in the event of such an occurrence. Reluctantly, the Earth agreed, but required the four droplets to stay beyond the Kuiper Belt. Moreover, each droplet had to be accompanied by a human probe, so that the droplets’ locations and orbits were known at all times. Thus, in the event of a droplet attack, the Earth would have about fifty hours of advance warning. Of these four droplets, two eventually followed Gravity to hunt Blue Space, and only two remained in the vicinity of the Kuiper Belt.

No one knew where the other six droplets had gone.

Trisolaris claimed that the six droplets had left the Solar System to rejoin the Trisolaran Fleet, but no one on Earth believed this.

Trisolarans were no longer creatures of transparent thought. During the past two centuries, they had learned a great deal about strategic thinking—lies, ruses, and tricks. This was perhaps the greatest benefit they gained from studying human culture.

Most people were convinced that the six droplets were hidden somewhere in the Solar System. But because the droplets were tiny, fast, and invisible to radar, they were extremely difficult to locate and track. Even by spreading oil films or using other advanced detection techniques, humans could only reliably detect droplets if they approached within 1/10 AU of the Earth, or fifteen million kilometers. Outside this sphere, the droplets were free to roam undetected.

At maximum speed, a droplet could cross fifteen million kilometers in ten minutes.

This was all the time the Swordholder would have to make a decision if dark forest deterrence broke down.

Deterrence Era, Year 62 November 28, 4:00 P.M. to 4:17 P.M.: Deterrence Center

With a deep rumble, the meter-thick heavy steel door opened and Cheng Xin and the others walked into the heart of the dark forest deterrence system.

More emptiness and openness greeted Cheng Xin. This was a semicircular hall, with the curved wall facing her. The surface was translucent, resembling ice. The floor and ceiling were pure white. Cheng Xin’s first thought was that she stood in front of an empty, iris-less eye, exuding a desolate sense of loss.

Then she saw Luo Ji.

Luo Ji sat cross-legged on the ground in the middle of the white hall, facing the curved wall. His long hair and beard, combed neatly, were also white, almost merging with the white wall. The whiteness everywhere contrasted strongly with his black Zhongshan suit.[5] Sitting there, he appeared as a stable upside-down T, a lonely anchor on a beach, immobile under the winds of time howling overhead and before the roaring waves of the ages, steadfastly waiting for a departed ship that would never return. In his right hand, he held a red ribbon, the hilt of his sword: the switch for the gravitational wave broadcast. His presence gave the empty eye of this room an iris. Though he was but a black dot, the desolate sense of loss was relieved, giving the eye a soul. Luo Ji sat facing the wall so that his own eyes were invisible, and he did not react to his visitors.

It was said that Master Batuo, the founder of Shaolin Monastery, had meditated in front of a wall for ten years until his shadow was carved into the stone. If so, Luo Ji could have inscribed his own shadow into this wall five times.

The PDC chair stopped Cheng Xin and the fleet chief of staff. “Still ten minutes until the handover,” he whispered.

In the last ten minutes of his fifty-four-year career as the Swordholder, Luo Ji remained steadfast.

At the beginning of the Deterrence Era, Luo Ji had enjoyed a brief period of happiness. He had been reunited with his wife, Zhuang Yan, and daughter, Xia Xia, and relived the joy of two centuries ago. But within two years, Zhuang Yan took the child and left Luo Ji. There were many stories told about her reasons. A popular version went like this: While Luo Ji remained a savior in the eyes of the public, his image had already transformed in the minds of those he loved the most. Gradually, Zhuang Yan had come to realize that she was living with a man who had already annihilated one world and held the fate of two more in his hand. He was a strange monster who terrified her, and so she left with their child. Another popular story said that Luo Ji left them, instead, so that they could live a normal life. No one knew where Zhuang Yan and their child had gone—they were probably still alive, living tranquil, ordinary lives somewhere.

His family had left him at the time when gravitational wave transmitters took over the task of deterrence from the circumsolar ring of nuclear bombs. Thereafter, Luo Ji embarked on his long career as the Swordholder.

In this cosmic arena, Luo Ji faced not the fancy moves of Chinese sword fighting, resembling dance more than war; nor the flourishes of Western sword fighting, designed to show off the wielder’s skill; but the fatal blows of Japanese kenjutsu. Real Japanese sword fights often ended after a very brief struggle lasting no more than half a second to two seconds. By the time the swords had clashed but once, one side had already fallen in a pool of blood. But before this moment, the opponents stared at each other like statues, sometimes for as long as ten minutes. During this contest, the swordsman’s weapon wasn’t held by the hands, but by his heart. The heart-sword, transformed through the eyes into the gaze, stabbed into the depths of the enemy’s soul. The real winner was determined during this process: In the silence suspended between the two swordsmen, the blades of their spirits parried and stabbed as soundless claps of thunder. Before a single blow was struck, victory, defeat, life, and death had already been decided.

Luo Ji stared at the white wall with just such an intense glare, aimed at a world four light-years away. He knew that the sophons could show his gaze to the enemy, and his gaze was endowed with the chill of the underworld and the heaviness of the rocks above him, endowed with the determination to sacrifice everything. The gaze made the enemy’s heart palpitate and forced them to give up any ill-considered impulse.

There was always an end to the gaze of the swordsmen, a final moment of truth in the contest. For Luo Ji, one participant in this universal contest, the moment when the sword was swung for the first and last time might never arrive.

But it could also happen in the next second.

In this manner, Luo Ji and Trisolaris stared at each other for fifty-four years. Luo Ji had changed from a carefree, irresponsible man into a true Wallfacer, who faced his wall for more than half a century; the protector of Earth civilization who, for five decades, was ready to deal the fatal blow at a moment’s notice.

Throughout this time, Luo Ji had remained silent, not uttering a single word. As a matter of fact, after a person ceased to speak for ten or fifteen years, he lost his powers of speech. He might still be able to understand language, but he would not be able to speak. Luo Ji certainly could no longer speak; everything he had to say, he put into his gaze against the wall. He had turned himself into a deterrence machine, a mine ready to explode on contact at each and every moment during the long years of the past half century, maintaining the precarious balance of terror between two worlds.

“It is time to hand over the final authority for the gravitational wave universal broadcast system.” The PDC chair broke the silence solemnly.

Luo Ji did not move from his pose. The fleet chief of staff walked over, intending to help him get up, but Luo lifted a hand to stop him. Cheng Xin noticed that the motion of his arm was strong, energetic, without a hint of the hesitation one might expect in a centenarian. Then, Luo Ji stood up by himself, his posture steady. Cheng Xin was surprised to see that Luo Ji did not push against the ground with his hands as he uncrossed his legs and stood up. Even most young men couldn’t perform such a motion effortlessly.

“Mr. Luo, this is Cheng Xin, your successor. Please pass the switch to her.”

Luo Ji stood tall and straight. He looked at the white wall, which he had stared at for more than half a century, for a few more seconds. Then he bowed slightly.

He was paying his respects to his enemy. To have stared at each other across an abyss of four light-years for half a century had bonded them by a link of destiny.

Then he turned to face Cheng Xin. The old and new Swordholders stood apart, silently. Their eyes met for only a moment, but in that moment, Cheng Xin felt a sharp ray of light sweeping across the dark night of her soul. In that gaze, she felt as light and thin as a sheet of paper, even transparent. She could not imagine what kind of enlightenment the old man in front of her had achieved after fifty-four years of facing the wall. She imagined his thoughts precipitating, becoming as dense and heavy as the crust above them or as ethereal as the blue sky above that. She had no way to know, not until and unless she herself had walked the same path. Other than a bottomless profundity, she could not read his gaze.

With both hands, Luo Ji handed over the switch. With both hands, Cheng Xin accepted this heaviest object in the history of the Earth. And so, the fulcrum upon which two worlds rested moved from a 101-year-old man to a 29-year-old woman.

The switch retained the warmth from Luo Ji’s hand. It really did resemble the hilt of a sword. It had four buttons, three on the side and one at the end. To prevent accidental activation, the buttons required some strength to press, and they had to be pressed in a certain order.

Luo Ji backed up two steps and nodded at the three people in front of him. With steady, strong strides, he walked toward the door.

Cheng Xin noticed that, throughout the entire process, no one offered a word of thanks to Luo Ji for his fifty-four years of service. She didn’t know if the PDC chair or the fleet chief of staff meant to say something, but she could not recall any of the rehearsals for the ceremony including plans for thanking the old Swordholder.

Humankind did not feel grateful to Luo Ji.

In the lobby, a few black-suited men stopped Luo Ji. One of them said, “Mr. Luo, on behalf of the Prosecution for the International Tribunal, we inform you that you have been accused of suspected mundicide. You are under arrest and will be investigated.”

Luo Ji did not even spare them a glance as he continued to walk toward the elevator. The prosecutors stepped aside instinctively. Perhaps Luo Ji did not even notice them. The sharp light in his eyes had been extinguished, and in its place was a tranquility like the glow of a sunset. His three-century-long mission was finally over, and the heavy load of responsibility was off his shoulders. From now on, even if the feminized humankind saw him as a devil and a monster, they all had to admit that his victory was unsurpassed in the entire history of civilization.

The steel door had remained open, and Cheng Xin heard the words spoken in the lobby. She felt an impulse to rush over and thank Luo Ji but stopped herself. Dejectedly, she watched him disappear into the elevator.

The PDC chair and the fleet chief of staff left as well, saying nothing.

With a deep rumble, the steel door closed. Cheng Xin felt her previous life seep out of the narrowing crack in the door like water escaping from a funnel. When the door shut completely, a new Cheng Xin was born.

She looked at the red switch in her hand. It was already a part of her. She and it would be inseparable from now on. Even when she slept, she had to keep it by her pillow.

The white, semicircular hall was deathly silent, as though time was sealed in here and no longer flowed. It really did resemble a tomb. But this would be her entire world from now on. She decided that she had to give life to this place. She didn’t want to be like Luo Ji. She wasn’t a warrior, a duelist; she was a woman, and she needed to live here for a long time—perhaps a decade, perhaps half a century. Indeed, she had been preparing for this mission her whole life. Now that she stood at the starting point of her long journey, she felt calm.

But fate had other ideas. Her career as the Swordholder, a career she had been preparing for since her birth, lasted only fifteen minutes from the moment she accepted the red switch.

The Final Ten Minutes of the Deterrence Era, Year 62 November 28, 4:17:34 P.M. to 4:27:58 P.M.: Deterrence Center

The white wall turned bloody red, as though the hellish magma behind it had burned through. Highest alert. A line of white text appeared against the red background, each character a terrifying scream.

Incoming strong-interaction space probes detected.

Total number: 6.

One is headed toward the L1 Lagrangian point between the Earth and the Sun.

The other 5 are headed for the Earth in a 1-2-2 formation.

Speed: 25,000 km/s. Estimated arrival time at the surface: 10 minutes.

Five floating numbers appeared next to Cheng Xin, glowing with a green light. These were holographic buttons: Pressing any of them would bring up a corresponding floating window displaying more detailed information gathered from the advance warning system sweeping the region of space within fifteen million kilometers out from the Earth. The Solar System Fleet General Staff analyzed the data and passed it on to the Swordholder.

Later, Earth would learn that the six droplets had been hiding just outside the fifteen-million-kilometer advance-warning zone. Three of them had relied on solar interference from the Sun to avoid detection, and the other three had disguised themselves in the orbiting space trash scattered in this region. Most of the space trash consisted of spent fuel from the early fusion reactors. Even without these measures, it would have been nearly impossible for the Earth to discover them outside the advance-warning zone because people had always assumed that the droplets were hiding in the asteroid belt, farther away.

The thunderclap that Luo Ji had been waiting for for half a century arrived within five minutes of his departure, and struck Cheng Xin.

Cheng Xin didn’t bother pressing any of the holographic buttons. She didn’t need any more information.

Right away, she understood the profundity of her error. In the depths of her subconscious, the vision she had held of the mission of the Swordholder had always been utterly, completely wrong. To be sure, she had always planned for the worst, or at least made an effort to do so. Guided by specialists from the PDC and the fleet, she had studied the deterrence system in detail and discussed various possible scenarios with strategists. She had imagined scenarios even worse than the current one.

But she had also committed a fatal error, an error that she did not and could not have realized. The error, however, was also the very reason she had been elected to be the second Swordholder.

In her subconscious, she had never truly accepted that the events facing her now were possible.

Average distance of incoming formation of strong-interaction space probes: approximately 14 million kilometers. The closest one is at 13.5 million kilometers. Estimated arrival time at the surface: nine minutes.

In Cheng Xin’s subconscious, she was a protector, not a destroyer; she was a woman, not a warrior. She was willing to use the rest of her life to maintain the balance between the two worlds, until the Earth grew stronger and stronger with Trisolaran science, until Trisolaris grew more and more civilized with Earth culture, until one day, a voice told her: Put down that red switch and return to the surface. The world no longer needs dark forest deterrence, no longer needs a Swordholder.

When she faced that distant world as the Swordholder, Cheng Xin, unlike Luo Ji, did not feel this was a life-or-death contest. She thought of it as a game of chess. She would sit tranquilly before the chessboard, thinking of all the openings, anticipating the opponent’s attacks, and devising her own responses. She was ready to spend her life playing this game.

But her opponents hadn’t bothered to move any pieces on the board. Instead, they had simply lifted the chessboard and smashed it at her head.

The moment Cheng Xin accepted the red switch from Luo Ji, the six droplets had begun accelerating at maximum power toward the Earth. The enemy did not waste a single second.

Average distance of incoming formation of strong-interaction space probes: approximately 13 million kilometers. The closest one is at 12 million kilometers. Estimated arrival time at the surface: eight minutes.

Blankness.

Average distance of incoming formation of strong-interaction space probes: approximately 11.5 million kilometers. The closest one is at 10.5 million kilometers. Estimated arrival time at the surface: seven minutes.

Blankness, nothing but blankness. In addition to the white hall and the white letters, everything else around her had also turned a blank white. Cheng Xin seemed to be suspended in a milky universe, just like a bubble of milk sixteen billion light-years across. In this vast blankness, she found nothing to hold on to.

Average distance of incoming formation of strong-interaction space probes: approximately 10 million kilometers. The closest one is at 9 million kilometers. Estimated arrival time at the surface: six minutes.

What was she supposed to do?

Average distance of incoming formation of strong-interaction space probes: approximately 9 million kilometers. The closest one is at 7.5 million kilometers. Estimated arrival time at the surface: five minutes.

The blankness began to dissipate. The forty-five-kilometer-thick crust above her reasserted its presence: sedimentary time. The lowest stratum, or the layer immediately above the Deterrence Center, had probably been deposited four billion years ago. The Earth had been born only five hundred million years before that. The turbid ocean was in its infancy, and nonstop flashes of lightning struck its surface; the Sun was a fuzzy ball of light in a haze-veiled sky, casting a crimson reflection over the sea. At short intervals, other bright balls of light streaked across the sky, crashing into the sea and trailing long tails of fire; these meteor strikes caused tsunamis that propelled gigantic waves to smash onto continents still laced with rivers of lava, raising clouds of vapor generated by fire and water that dimmed the Sun….

In contrast to this hellish but magnificent sight, the turbid water brewed a microscopic tale. Here, organic molecules were born from lightning flashes and cosmic rays, and they collided, fused, broke apart again—a long-lasting game played with building blocks for five hundred million years. Finally, a chain of organic molecules, trembling, split into two strands. The strands attracted other molecules around them until two identical copies of the original were made, and these split apart again and replicated themselves…. In this game of building blocks, the probability of producing such a self-replicating chain of organic molecules was so minuscule that it was as if a tornado had picked up a pile of metallic trash and deposited it as a fully-assembled Mercedes-Benz.

But it happened, and so, a breathtaking history of 3.5 billion years had begun.

Average distance of incoming formation of strong-interaction space probes: approximately 7.5 million kilometers. The closest one is at 6 million kilometers. Estimated arrival time at the surface: four minutes.

The Archean Eon was followed by the Proterozoic Eon, each billions of years; then the Paleozoic: the Cambrian’s seventy million years, the Ordovician’s sixty million years, the Silurian’s forty million years, the Devonian’s fifty million years, the Carboniferous’s sixty-five million years, and the Permian’s fifty-five million years; then the Mesozoic: the Triassic’s thirty-five million years, the Jurassic’s fifty-eight million years, and the Cretaceous’s seventy million years; then the Cenozoic: the Tertiary’s 64.5 million years and the Quaternary’s 2.5 million years.

Then humanity appeared. Compared to the eons before, mankind’s history was but the blink of an eye. Dynasties and eras exploded like fireworks; the bone club tossed into the air by an ape turned into a spaceship. Finally, this 3.5-billion-year-long road full of trials and tribulations stopped in front of a tiny human individual, a single person out of the one hundred billion people who had ever lived on the Earth, holding a red switch.

Average distance of incoming formation of strong-interaction space probes: approximately 6 million kilometers. The closest one is at 4.5 million kilometers. Estimated arrival time at the surface: three minutes.

Four billion years were layered on top of Cheng Xin, suffocating her. Her subconscious tried to reach the surface, to catch a breath above it. In her subconscious, the surface was teeming with life, the most prominent form being the giant reptiles, including dinosaurs. Densely, they packed the ground, all the way to the horizon. Among the dinosaurs, between their legs and under their bellies, were the mammals, including humans. Still lower, under and between countless pairs of feet, were surging black currents of water: innumerable trilobites and ants…. In the sky, hundreds of billions of birds formed a dark, swirling vortex that blotted out the firmament, and giant pterodactyls could be seen among them from time to time….

Everything was deathly quiet. The eyes were the most terrifying: the eyes of dinosaurs; the eyes of trilobites and ants; the eyes of birds and butterflies; the eyes of bacteria…. The humans alone possessed one hundred billion pairs of eyes, equal to the number of stars in the Milky Way. Among them were the eyes of ordinary men and women, and the eyes of Da Vinci, Shakespeare, and Einstein.

Average distance of incoming formation of strong-interaction space probes: approximately 4.5 million kilometers. The closest one is at three million kilometers. Estimated arrival time at the surface: two minutes.

Two of the probes are headed for Asia, two others for North America. The last one is aimed at Europe.

Pressing the switch would end the progress of 3.5 billion years. Everything would disappear in the eternal night of the universe, as though none of it had ever existed.

That baby seemed to be back in her arms: soft, cuddly, warm, his face moist, smiling sweetly, calling her mama.

Average distance of incoming formation of strong-interaction space probes: approximately 3 million kilometers. The closest one is at 1.5 million kilometers, and it is rapidly decelerating. Estimated arrival time at the surface: one minute and thirty seconds.

“No—” Cheng Xin screamed, and threw the switch away. She watched it slide across the ground, as though watching a devil.

Strong-interaction space probes approaching lunar orbit and continuing to decelerate. Extending their trajectories suggests that their targets are the gravitational wave broadcasting stations in North America, Europe, and Asia, and Gravitational Wave Universal Broadcast System Control Station Zero. Estimated impact on the surface: thirty seconds.

Like a strand of spider silk, these final moments stretched out endlessly. But Cheng Xin did not vacillate; she had already made up her mind. This wasn’t a decision born of thought, but buried deep in her genes. These genes could be traced to four billion years ago, when the decision was first made. The subsequent billions of years only strengthened it. Right or wrong, she knew she had no other choice.

It was good that release was at hand.

A great jolt tumbled her to the ground: The droplets had penetrated the crust. She felt as though the solid rocks around her had vanished, and the Deterrence Center was on top of a giant drumhead. She closed her eyes and imagined the sight of a droplet passing through the crust like a fish swimming through water, waiting for the arrival at cosmic velocity of the perfectly smooth devil that would turn her and everything around her into molten lava.

But the quaking stopped after a few violent beats, like a drummer punctuating the end of the piece.

The red light on the screen faded, replaced by the white background from before. The room seemed brighter and more open. A few lines of black text appeared:

North American gravitational wave transmitter destroyed.

European gravitational wave transmitter destroyed.

Asian gravitational wave transmitter destroyed.

Solar radio-amplification function suppressed on all bands.

Silence once again reigned over everything, except the faint sound of water trickling somewhere. A pipe had burst during the quake.

Cheng Xin understood that the droplet attack on the Asian gravitational wave transmitter had caused the earthquake. That antenna was about twenty kilometers from here and was also deeply buried.

The droplets had not even bothered attacking the Swordholder.

The black text disappeared. After some moments of blankness, a last screen of text faded in:

Gravitational wave universal broadcast system cannot be recovered. Dark forest deterrence has been terminated.

Post-Deterrence Era, First Hour A Lost World

Cheng Xin rode the elevator to the surface. Exiting the elevator station, she saw the plaza where the deterrence handover ceremony had taken place an hour ago. All the attendees had left, and the place was empty save for the long shadows cast by the flagpoles. The flags of the UN and the Solar System Fleet hung from the two tallest poles, and behind them were the flags of the various nations. The flags continued to flap tranquilly in the light breeze. Beyond them was the endless Gobi Desert. A few twittering birds landed in a stand of tamarisk nearby. In the distance, she could see the rolling Qilian Mountains, the snow cover on a few peaks giving them a silvery highlight.

Everything seemed the same, but this world no longer belonged to humans.

Cheng Xin didn’t know what to do. No one had contacted her after the end of deterrence. The Swordholder no longer existed, just like deterrence.

She walked forward aimlessly. When she exited the gates of the compound, two guards saluted her. She was terrified of facing people, but she saw nothing but curiosity in their eyes—they didn’t yet know what had happened. Regulations permitted the Swordholder to come onto the surface for brief intervals, and they must have thought she had come up to investigate the quake. Cheng Xin saw a few military officers standing next to a flying transport parked by the gate. They weren’t even looking at her, merely in the direction she had come from. One of them pointed in that direction.

She turned around and saw the mushroom cloud on the horizon. Formed by the earth and dust thrown up from deep underground, it was very thick, appearing almost solid. It looked so out of place in the serene scene that it resembled a bad Photoshop job. A closer examination led Cheng Xin to imagine it as an ugly bust showing a strange expression in the setting sun. That was where the droplet had penetrated the Earth.

Someone called her name. She turned and saw 艾 AA running toward her. Dressed in a white jacket, her hair waving in the wind, she panted and told Cheng Xin that she had come to see her, but the sentries wouldn’t let her in.

“I’ve brought some flowers for your new place,” she said, pointing at her parked car. Then she turned to the mushroom cloud. “Is that a volcano? Did that cause the earthquake just now?”

Cheng Xin wanted to pull AA into her arms and cry, but she controlled herself. She wanted to delay the moment when this happy girl found out the truth, wanted to let the reverberations of the good times that had just ended linger a bit longer.

Excerpt from A Past Outside of Time Reflections on the Failure of Dark Forest Deterrence

The most important factor in the failure of deterrence was, of course, electing the wrong Swordholder. This is a topic that will be addressed elsewhere in a dedicated chapter. For now, let’s focus on the technical weaknesses in the system design that contributed to the failure.

After the failure, most people immediately pointed to the small number of gravitational wave transmitters as a cause, and blamed people from the early Deterrence Era for dismantling nineteen of the twenty-three completed transmitters. But this reaction represented a failure to grasp the substance of the problem. From data gathered during the droplet attack, a droplet needed slightly more than ten seconds on average to penetrate the crust and destroy a transmitter. Even if the planned one hundred transmitters had been completed and deployed, it wouldn’t have taken long for droplets to destroy the entire system.

The key was that the system could be destroyed. Humankind had had a chance to build an indestructible gravitational wave universal broadcast system, but hadn’t taken it.

The problem wasn’t the number of transmitters, but where they were deployed.

Imagine if the twenty-three transmitters had not been built on or below the surface, but in space—that is, twenty-three spaceships like Gravity. Normally, the ships would be scattered around the Solar System. Even if the droplets had conducted a surprise attack, it would be difficult for them to destroy all of them. One or more of the ships would have time to escape into deep space.

This would have greatly increased the degree of deterrence for the whole system, in a way that would not have been dependent on the Swordholder. The Trisolarans would have known that they controlled insufficient forces within the Solar System to completely destroy the deterrence system, and would have behaved with far more restraint.

Regrettably, there was only one Gravity.

There were two reasons that more ships with transmitters weren’t built: First, there was the “Sons of the Earth” attack on the transmitter in Antarctica. Spaceships were deemed even more vulnerable to threats from extremist humans than underground stations. Second, it was a matter of economics. Since gravitational wave antennas were immense, they had to serve as the hull of the ship itself. Thus, the antenna had to be constructed out of materials that met the requirements of spaceflight, which increased costs many times. Gravity itself cost almost the equivalent of the twenty-three ground-based transmitters added together. Moreover, the hull of the ship itself could not be refreshed; when the vibrating string made of degenerate matter that ran the length of the ship reached its fifty-year half-life limit, a completely new gravitational wave ship had to be built.

But the deeper root cause could only be found in the minds of humankind. Never explicitly stated, and perhaps not even consciously understood, a gravitational wave ship was too powerful—so powerful that it terrified its creator. If something—a droplet attack or something else—forced such ships to depart for deep space, and they could never return to the Solar System due to the presence of enemy threats, they would turn into copies of Blue Space and Bronze Age, or something even more horrific. Each gravitational wave ship, with its no-longer-human crew, would also possess the power to broadcast to the universe (though limited by the half-life of the vibrating string), thus controlling the fate of humanity. A frightful instability would be permanently scattered among the stars.

At its root, this fear was a fear of dark forest deterrence itself. This was characteristic of ultimate deterrence: The deterrer and the deteree shared the same terror of deterrence itself.

Post-Deterrence Era, First Hour A Lost World

Cheng Xin walked toward the officers and asked them to take her to the site of the eruption. A lieutenant colonel in charge of security for the compound immediately dispatched two cars: one to take her, the other to carry a few guards for security. Cheng Xin asked AA to stay and wait for her, but AA insisted on coming and got into the car.

The flying cars hovered barely above the ground and headed to the mushroom cloud at a low speed. AA asked the driver what was wrong, but he didn’t know. The volcano had erupted twice, a few minutes apart. He thought it might be the first time in recorded history that a volcano had erupted within China’s borders.

He couldn’t have imagined that the “volcano” had once hidden the strategic fulcrum for the world: the gravitational wave antenna. The first eruption was caused by the impact of the droplet penetrating the crust. After destroying the antenna, it retraced its path and emerged from the ground, causing a second eruption. The eruptions were due to the droplet releasing its tremendous kinetic energy in the ground, not an outburst of material from the mantle, so they were very brief. The extremely high velocity of the droplet meant that it could not be observed by the naked eye as it penetrated or emerged from the ground.

Small smoking pits dotted the Gobi as it passed beneath the car: mini-impact craters from the lava and heated rocks that had been thrown up by the eruption. As they proceeded, the pits grew denser, and a thick layer of smoke hovered over the Gobi, revealing burning stands of tamarisk here and there. Though few people lived out here they occasionally saw old buildings collapsed by the quake. The whole scene resembled a battlefield where the fighting had just finished.

The cloud had dissipated a bit by now and no longer looked like a mushroom—it was more like a head of unkempt hair whose tips were colored crimson by the setting sun. A security line stopped the cars as they approached, and they had to land. But Cheng Xin persisted, and the sentries let her through. The soldiers didn’t know that the world had already fallen, and they still respected Cheng Xin’s authority as the Swordholder. They did, however, stop AA, and no matter how she screamed and struggled, they would not let her pass.

The steady wind had already driven most of the dust away, but the smoke broke the light of the setting sun into a series of flickering shadows. Cheng Xin walked about a hundred meters through the shadows until she reached the edge of a giant crater. Shaped like a funnel, the crater was forty or fifty meters deep at the center. Thick clouds of white smoke still poured out of it, and the bottom of the crater gave off a dim red molten glow: a pool of lava.

Forty-five kilometers below, the gravitational wave antenna, a cylinder with a length of fifteen hundred meters and a diameter of fifty meters suspended in an underground cave with magnetic levitation, had been smashed into smithereens and swallowed by the red-hot lava.

This should have been her fate. It would have been the best ending for a Swordholder who had given up the power to deter.

The red glow at the bottom of the crater attracted Cheng Xin. Just one more step, and she would achieve the release that she desired. As waves of heat buffeted her face, she stared at the dim red pool, mesmerized, until peals of laughter from behind her shook her out of her musing.

She turned around. In the flickering sunlight filtered by the smoke, a slender figure approached her. She didn’t recognize the newcomer until she was very close: Sophon.

Other than the pale, lovely face, the robot looked completely different from the last time Cheng Xin had seen her. She was dressed in desert camouflage, and her hair, once tied up in a neat bun decorated with flowers, had been cut in a short and efficient style. Around her neck was the black scarf of a ninja, and on her back was strapped a long katana. She looked valiant and heroic, but the extreme femininity that she exuded had not vanished completely: Her postures and movements were still soft and gentle like water, but now they were also suffused with a glamorous air of killing and death, like a pliant but fatal noose. Even the heat spilling from the crater could not dispel the chill she brought.

“You acted just as we anticipated,” Sophon said, sneering. “Don’t be too hard on yourself. The fact is that humankind chose you, and they chose this result. Out of all the members of the human race, you’re the only innocent.”

Cheng Xin’s heart jumped. She didn’t feel comforted, but she had to admit that this lovely devil had a power that penetrated her soul.

Cheng Xin saw AA approach. She had apparently found out or guessed what had really happened. AA’s eyes burned with fury as she stared at Sophon; she picked up a rock from the ground with both hands and smashed the back of Sophon’s skull with it. But Sophon turned around and brushed the rock away like a mosquito. AA cursed at Sophon using every profane word she could think of, and went for another rock. Sophon unsheathed the katana on her back, easily pushing off the pleading Cheng Xin with her other hand, and twirled the katana. It sliced through the air, faster than the blades of an electric fan, whining loudly. When she stopped, strands of AA’s hair drifted down around her head. AA stood frozen in place, terrified, her shoulders hunched.

Cheng Xin remembered that she had seen Sophon’s katana in that eastern leaf-house shrouded in fog and cloud. Back then, it, and two shorter swords, had rested on a refined wooden stand next to the tea table, looking more decorative than deadly.

“Why?” Cheng Xin muttered, as if asking herself.

“Because the universe is not a fairy tale.”

Rationally, Cheng Xin understood that, had the balance maintained by deterrence continued, the brighter future belonged to humankind, not Trisolaris. But in her subconscious, the universe remained a fairy tale, a fairy tale about love. Her biggest mistake was not looking at the problem from the perspective of the enemy.

From Sophon’s gaze, Cheng Xin finally understood why she had been kept alive.

As the gravitational wave broadcast system had been destroyed and the sun’s ability to amplify radio waves had been suppressed, a living Cheng Xin posed no threat. On the other hand, in the unlikely event that humans still possessed some other method of broadcasting to the universe unknown to Trisolaris, eliminating the Swordholder might cause others to activate the broadcast. As long as the Swordholder was alive, however, the probability of that happening was virtually nil: Others would have a reason and excuse to shirk their responsibility.

Instead of the deterrer, Cheng Xin had been turned into a safety shield. The enemy had seen through her completely.

She was a fairy tale.

“Don’t celebrate too early,” AA said to Sophon, having recovered some of her courage. “We still have the spaceship Gravity.”

Sophon returned the katana to its sheath on her back in a single, smooth motion. “Foolish girl, Gravity has been destroyed. It happened an hour ago, when the handover occurred a light-year away. I regret that I can’t show you the wreckage because the sophons are in a blind zone.”

The Trisolarans had been planning and preparing for this moment for a long time. The exact time for the handover had been determined five months ago, before the sophons accompanying Gravity had entered the blind zone. The two droplets with Gravity had already received the order to destroy the ship at the moment of the handover.

“I’m leaving,” said Sophon. “Please convey to Dr. Luo Ji the deepest respect of all of Trisolaris. He was a powerful deterrer, a great warrior. Oh, and if you get the chance, also give Mr. Thomas Wade our regrets.”

Cheng Xin looked up, surprised.

“In our personality studies, your degree of deterrence hovered around ten percent, like a worm wriggling on the ground. Luo Ji’s degree of deterrence was always around ninety percent, like a fearsome cobra poised to strike. But Wade—” Sophon gazed at the setting sun behind the smoke, only a sliver of which now was above ground. Terror glinted from her eyes. She shook her head vigorously, as though trying to chase away a mirage in her mind. “He had no curve at all. No matter what the other environmental parameters were, his degree of deterrence stayed at one hundred percent! What a devil! If he had become the Swordholder, none of this would have been possible. This peace would have had to last. We’ve already waited sixty-two years, but we’d have had to keep on waiting, maybe for fifty more years, or even longer. And then Trisolaris would face an Earth equal to us in technology and power. We’d have to compromise…. However, we knew that humanity would choose you.”

Sophon walked away, taking large strides. She paused some distance away and turned around, calling out to the silent Cheng Xin and AA. “Get ready to go to Australia, you pitiful bugs.”

Post-Deterrence Era, Day 60 A Lost World

On the thirty-eighth day after the end of deterrence, the Ringier-Fitzroy observation station at the outer rim of the asteroid belt discovered 415 new trails in the interstellar dust cloud near the Trisolaran star system. Apparently, Trisolaris had sent a second fleet toward the Solar System.

This second fleet had left Trisolaris five years ago, and passed through the dust cloud four years ago. This had been a huge risk on Trisolaris’s part—if they couldn’t destroy humanity’s dark forest deterrence system within five years, the discovery of this fleet might have led to the activation of the deterrence broadcast. This meant that as long ago as five years, Trisolaris already had sensed the shifting mood toward dark forest deterrence among humanity and correctly predicted the kind of second Swordholder that would be elected.

History seemed to have been reset; a new cycle had begun.

The end of deterrence once again cast the future of humankind into darkness, but, just like in the first crisis over two centuries earlier, people did not connect this darkness with their individual fates. Based on analysis of the trails, the Second Trisolaran Fleet’s velocity wasn’t so different from that of the First Trisolaran Fleet. Even if they could accelerate more, the fleet wouldn’t arrive at the Solar System for at least two or three centuries. Everyone alive would be able to live out the remainder of their lives in peace. After the lessons taught by the Great Ravine, modern men and women would never again sacrifice the present for the future.

But this time, humanity wasn’t so fortunate.

Three days after the Second Trisolaran Fleet left the interstellar cloud, the observation system detected 415 trails in the second interstellar cloud. These trails couldn’t belong to a different fleet. The First Trisolaran Fleet had taken five years to go from the first dust cloud to the second, while the Second Trisolaran Fleet had taken only six days.

The Trisolarans had achieved lightspeed.

Analysis of the trails in the second interstellar dust cloud confirmed that they continued to extend through the cloud at lightspeed. At such high velocities, the trails left by the ships’ impacts became particularly prominent.

Timing wise, it appeared that the fleet had entered lightspeed as soon as it exited the first dust cloud; there didn’t appear to be a stage during which it accelerated.

If that was true, then the Second Trisolaran Fleet should have already or almost reached the Solar System. Using midsized telescopes, it was possible to see a patch of 415 bright lights about six thousand AU from the Earth. These were the lights generated by deceleration. Apparently the ships’ propulsion systems were conventional. The fleet’s velocity was now only 15 percent of the speed of light. This was evidently the fastest speed that still permitted safe deceleration before arriving at the Solar System. Based on the observed velocity and deceleration, the Second Trisolaran Fleet would arrive at the edge of the Solar System in one year.

This was a bit puzzling. It appeared as if the Trisolar ships were capable of entering and dropping out of lightspeed within an extremely short period of time, but they chose not to do so too close to the Trisolaran star system or the Solar System. After the fleet had left Trisolaris, the ships accelerated under conventional power for an entire year, until they were about six thousand AU from home, before entering lightspeed. Similarly, they dropped out of lightspeed at the same distance from the Solar System and switched to conventional deceleration. This distance could be covered in a month at lightspeed, but the fleet chose to spend a year traversing it. The cruise of the Second Trisolaran Fleet would thus take two years longer than it would if the entire voyage were conducted at lightspeed.

Only one explanation for this curious decision came to mind: It was motivated by a desire not to harm either solar system during the process of entering and dropping out of lightspeed. The safe radius appeared to be two hundred times the distance from the Sun to Neptune. This suggested that the power generated by the drives was two orders of magnitude greater than a star, which seemed unimaginable.

Excerpt from A Past Outside of Time Technology Explosion on Trisolaris

Exactly when the rate of Trisolaran technological progress had shifted from constant to explosive was a mystery. Some scholars believed that the acceleration began before the Crisis Era; others believed that the forward leap didn’t happen until the Deterrence Era. There was, however, general consensus on the causes for the technology explosion.

First, Earth civilization had a tremendous impact on Trisolaran civilization—on this point, at least, the Trisolarans likely didn’t lie. Since the arrival of the first sophon, the massive inflow of human culture profoundly changed Trisolaris, and some human values resonated with the Trisolarans. Trisolaran society broke down the barriers to scientific progress imposed by the extreme totalitarian political system that had been adopted as a reaction to the chaotic eras, encouraged freedom of thought, and began to respect the individual. These changes might have triggered ideological transformation movements akin to the Renaissance in that distant world, leading to leaps in scientific and technological progress. This must have been a glorious period in Trisolaran history, but the specific details were unknown.

A second possibility was only a guess: The exploratory sophon missions sent in other directions in the universe were not fruitless, as the Trisolarans claimed. Before being blinded, they might have found at least one other civilized world. If so, Trisolarans might have not only received technological knowledge from this other civilization, but also important information about the condition of the dark forest in the universe. If so, Trisolaris far surpassed the Earth in every domain of knowledge.

Post-Deterrence Era, Day 60 A Lost World

For the first time since the end of deterrence, Sophon appeared. Still dressed in camouflage and wearing the katana on her back, she announced to the world that the Second Trisolaran Fleet would arrive in four years to complete the total conquest of the Solar System.

Trisolaran policy toward humanity had changed since the first crisis. Sophon announced that Trisolaris no longer intended to exterminate human civilization, but would create reservations for humans within the Solar System—specifically, they would let humanity live in Australia and on one-third of the surface of Mars. This preserved the basic living space needed for human civilization.

To prepare for the Trisolaran conquest in four years, Sophon declared that humanity must immediately begin to resettle. To accomplish the so-called “defanging” of humanity, and to prevent the reappearance of dark forest deterrence or similar threats in the future, humanity must be completely disarmed and resettle “naked.” No heavy equipment or facilities would be permitted in the reservations, and the resettlement must be completed within one year.

Human habitats on Mars and in space could accommodate about three million individuals at most; thus, the main destination for resettlement was Australia.

But most people still held on to the illusion that they would have at least a generation of tranquil life. After Sophon’s speech, no country responded, and no one actually emigrated.

Five days after this historical “Reservation Proclamation,” one of the five droplets cruising within the Earth’s atmosphere attacked three large cities in Asia, Europe, and North America. The purpose of the attacks wasn’t to destroy the cities, but to instill terror. The droplet passed straight through the giant forests of these cities, colliding with all hanging buildings that happened to be in the way. The struck buildings burned and then fell several hundred meters, like overripe fruits. Over three hundred thousand people died in the worst disaster since the Doomsday Battle.

People finally understood that, to the droplets, the human world was as fragile as eggs under a poised rock. Cities and large-scale facilities were defenseless. If the Trisolarans wanted, they could lay waste to every city, until the surface of the Earth was one large ruin.

As a matter of fact, humans had been working toward overcoming this disadvantage. Humans understood early on that only strong-interaction materials (SIM) could be used to defend against droplets. Before the termination of deterrence, research facilities on Earth and in the fleet could already produce small quantities of such material in laboratories, though large-scale manufacturing and utilization would not be possible for years. If humanity had had another ten years, production of large amounts of SIM would have been a reality. Although the propulsion systems of the droplets would still have been far beyond human capabilities, at least conventional missiles could have been made out of SIM to destroy the droplets by sheer numerical advantage. Alternatively, SIM could have been used to construct defensive screens. Even if the droplets had dared to attack these shields, they would have become one-time-use shells.

Alas, none of these visions would ever come true now.

Sophon made another speech, in which she explained that Trisolaris had changed its policy of extermination of humanity out of love and respect for human civilization. It was inevitable that resettlement of humanity to Australia would cause them to suffer somewhat for a period of time, but it would last only three to four years. After the arrival of the Trisolaran Fleet, the conquerors were capable of helping the four billion people in Australia live comfortably. Also, the conquerors would assist humanity in constructing additional habitats on Mars and in space. Five years after the arrival of the Trisolaran Fleet, humanity could begin to migrate in large numbers to Mars and space, a process projected to take fifteen years. By then, humanity would possess adequate living space, and the two civilizations would begin a life of peaceful coexistence.

But all of this depended on the successful accomplishment of the initial resettlement to Australia. If the relocation effort did not commence immediately, the droplets would continue to attack the cities. After the expiration of the one-year period, any humans found outside the reservations would be exterminated as invaders on Trisolaran territory. Of course, if humans left the cities and scattered across the continents, the five droplets alone would not be enough to locate and kill every single individual. But the Second Trisolaran Fleet arriving in four years would no doubt be able to.

“The glorious and resplendent civilization of Earth earned humanity this one chance at survival,” said Sophon. “Please treasure it.”

Thus began the Great Resettlement of all of humanity to Australia.

Post-Deterrence Era, Year 2 Australia

Cheng Xin stood in front of Elder Fraisse’s house and surveyed the Great Victoria Desert shimmering in the heat. Simple, just-completed shelter-houses were packed densely, as far as the eye could see. Under the noonday sun, the plywood and sheet-metal constructions seemed both brand-new and fragile, like origami toys scattered across the sand.

When James Cook had discovered Australia five centuries ago, he could never have imagined that, one day, all of humanity would be gathered on this empty, vast continent.

Cheng Xin and 艾 AA had come to Australia with the earliest wave of forced migrants. Cheng Xin could have gone to a big city like Canberra or Sydney for a relatively comfortable life, but she had insisted on living as an ordinary migrant and gone to the interior resettlement zone in the deserts near Warburton, where conditions were the roughest. She was touched that AA, who could also have gone to a big city, insisted on accompanying her.

Life in the resettlement zone was difficult. Near the beginning, when few people were there, it was still tolerable. The harassment by other people was far harder to bear than the material deprivations. At first, Cheng Xin and AA had a shelter-house all to themselves. But as additional migrants came, more people were packed into the shelter-house, until eight women in total shared it. The other six women had all been born during the paradise-like Deterrence Era. Here, for the first time in their lives, they encountered rationing of water and food, dead walls that did not come alive with information, rooms with no air-conditioning, public toilets and showers, bunk beds…. This was a society of absolute equality: Money had no use here, and everyone received exactly the same ration. They had only ever seen such austerity in historical films, and life in the resettlement zones felt like hell. Naturally, Cheng Xin became the target of their fury. Unprovoked, they would curse at her and accuse her of being a waste of space—after all, she had not been able to deter Trisolaris. Her worst sin had been giving up as soon as she received the warning: Had she activated the gravitational wave broadcast, the Trisolarans would have run away in terror, and at least humanity would enjoy a few more decades of happiness. Even if the broadcast led to the immediate destruction of the Earth, it would be better than the current conditions.

At the beginning, the abuse was merely verbal, but it soon turned physical, and they began to snatch Cheng Xin’s rations away from her. AA did all she could to protect her friend. She fought the other women, sometimes several times a day. Once, she grabbed the meanest one by the hair and slammed her head against a bedpost until blood covered her face. Thereafter, they left her and Cheng Xin alone.

But the enmity directed at Cheng Xin wasn’t limited to their roommates: The migrants in the shelter-houses nearby also came to harass her. Sometimes they threw stones at Cheng Xin’s shelter-house; sometimes a mob surrounded the shelter-house and shouted curses at her.

Cheng Xin bore all the abuse with equanimity. Indeed, the abuse even comforted her. As the failed Swordholder, she felt she deserved worse.

This persisted until an old man named Fraisse came and invited her and AA to move into his place. Fraisse was an Aboriginal man, over eighty years of age but still hale and hearty, with a white beard on his black face. As a native, he had been temporarily allowed to keep his own house. During the Common Era, he had been in charge of an organization for Aboriginal cultural preservation, and he had gone into hibernation at the beginning of the Crisis Era in order to continue his task in the future. When he awoke, he saw that his prediction had come true: The Australian Aboriginals and their culture were close to disappearing.

Fraisse’s house, built back in the twenty-first century, was old but solid and had a nice copse of trees nearby. Once they moved there, Cheng Xin and AA’s lives became much more stable. More importantly, the old man provided them with spiritual tranquility. He did not share the popular searing anger and bone-deep hatred toward the Trisolarans; indeed, he rarely talked about the crisis at all. All he said was, “Whatever people do, the gods remember.”

True. Even people still remembered whatever people did. Five centuries ago, civilized men of Earth—most of whom had actually been criminals in Europe—stepped onto this continent and shot the Aboriginal peoples in the woods for sport. Later, even when they recognized that their quarries were men and women, not beasts, the slaughter continued. The Aboriginal peoples had lived in this vast land for tens of thousands of years. By the time the white men arrived, the native population was more than a half million, but that number soon diminished to thirty thousand refugees who had to escape to the desolate western deserts to survive….

When Sophon proclaimed the establishment of “reservations,” people paid attention. It brought to mind the tragic fate of the native peoples of North America, another faraway continent where the arrival of civilized men of Earth brought sorrow.

When she first arrived at Fraisse’s, AA was curious about everything in the old house. It resembled a museum of Aboriginal culture. Everywhere there were rock and bark paintings, musical instruments made of wooden slats and hollow logs, woven grass skirts, boomerangs, spears, and other such objects. AA was most interested in a few pots of paint made of white clay and red and yellow ocher. She knew right away what they were for, and, dipping a finger into the pots, started to paint her own face. Then she began dancing in imitation of tribal dancers she had seen somewhere, making fearsome noises as she danced.

“This would have terrified those bitches living with us,” she said.

Fraisse laughed and shook his head. He explained that AA wasn’t imitating the Aboriginal peoples of Australia, but the Māori of New Zealand. Outsiders sometimes confused the two, but the Aboriginal peoples of Australia were gentle, while the Māori were fierce warriors. And, even so, she wasn’t imitating the Māori dance correctly, and had failed to capture their spirit. Fraisse then painted his own face into an impressive mask and took off his shirt, revealing a dark chest and powerful muscles that seemed incongruous with his advanced age. He picked up a taiaha from the corner of the house and began to dance a real war haka.

Cheng Xin and AA were mesmerized. Fraisse’s kind everyday demeanor disappeared, and he transformed into a threatening, awe-inspiring demon. His whole body seemed suffused with magnificent force. Every cry and foot stomp made the glass window panes quake in their frames, and the two women trembled. But it was his eyes that shocked them the most: Murderous chill and searing rage spewed from those wide-open orbs, combining the forces of typhoons and thunder in Oceania. His powerful gaze seemed to project earth-shattering shouts: “Do not run away! I will kill you! I will eat you!”

The haka over, Fraisse went back to his usual kind self. “For a Māori warrior, the key is to hold the enemy’s gaze. He must defeat the enemy first with his eyes, then kill him with the taiaha.” He came back and stood in front of Cheng Xin. “Child, you failed to hold the enemy’s gaze.” Then he patted her gently on the shoulder. “But, it’s not your fault. Really not your fault.”

The next day, Cheng Xin did something that surprised even herself: She went to see Wade.

Wade was sealing up the windows of a shelter-house with composite boards so that it could be used as a warehouse. One of his sleeves was empty. In this age, it would have been easy for him to acquire a prosthesis indistinguishable from the real thing, but for some reason, he had refused.

Two other prisoners—clearly also Common Era men—whistled at Cheng Xin. But once they realized who Cheng Xin had come to see, they shut up and went back to their work without looking up.

As Cheng Xin approached Wade, she was a bit surprised to see that while he was serving his sentence in harsh conditions, he looked much better groomed than the last time they met. He was clean-shaven and his hair was combed neatly. Prisoners in this age no longer wore uniforms, but his white shirt was the cleanest here, even more so than the shirts worn by the guards. Holding a few nails between his lips, he took them out one at a time with his left hand and pounded them into the composite boards with precise, forceful blows from the hammer. He glanced at Cheng Xin without changing his indifferent expression and went on working.

Cheng Xin knew right away that he had not given up. His ambitions, ideals, treachery, and whatever else was hidden in his heart, unknown to her—he had given up none of it.

Cheng Xin extended a hand to Wade. He glanced at her again, put down the hammer, spat out the nails, and deposited them in her hand. Then she handed him the nails one by one as he pounded them in, until they were all gone.

“Leave,” he said. He grabbed another handful of nails from the tool chest. He didn’t hand them over to Cheng Xin and didn’t put them in his mouth. Instead, he placed them on the ground next to his feet.

“I… I just…” Cheng Xin didn’t know what to say.

“I’m telling you to leave Australia.” Wade’s lips barely moved as he whispered. His gaze remained on the composite board. Anyone a little distance away would think he was concentrating on his work. “Hurry, before the resettlement is complete.”

Like he had many times three centuries ago, Wade had managed to stun Cheng Xin with a single sentence. Each time it was as if he had tossed her a knotted ball of string that she must untangle layer by layer before she could understand the complex meaning hidden within. But this time, Wade’s words made her shiver. She didn’t even have the courage to begin to untangle his riddle.

“Go.” Wade didn’t give her a chance to ask questions. Then he turned to her and once again revealed his special smirk, like a crack in a frozen-over pond. “Now I’m telling you to get out of this house.”

On the way back to Warburton, Cheng Xin saw the densely packed shelter-houses stretching to the horizon, saw the busy crowd laboring in the cracks between the shelter-houses. Suddenly, she felt her vision shift, as though she were watching everything from somewhere outside the world, and everything she saw turned into a writhing nest of ants. A nameless terror gripped her and the bright Australian sunlight seemed as cold as rain in winter.

Three months after the start of the Great Resettlement, more than a billion people had been relocated to Australia. Simultaneously, the governments of the nations of the world began to relocate to large Australian cities. The UN moved its headquarters to Sydney. Each government directed the resettlement of its own citizens, with the UN Resettlement Commission coordinating the efforts. In their new land, the migrants gathered into districts based on their nation of origin, and Australia became a miniature replica of the whole Earth. Other than the names of the largest cities, old place names were abandoned. Now “New York,” “Tokyo,” and “Shanghai” were nothing more than refugee camps full of basic shelter-houses.

No one had any experience in dealing with resettlement at such a large scale, either in the national governments or the UN, and many difficulties and dangers soon surfaced.

First, there was the problem of shelter. Leaders soon realized that even if all the construction materials in the world were shipped to Australia, and per capita space were limited to the dimensions of a bed, not even one-fifth of the final total population would have a roof over their heads. By the time five hundred million migrants were in Australia, there was no more material for building shelter-houses. They had to resort to erecting large tents, each of which was the size of a stadium and capable of housing more than ten thousand. But under such poor living and sanitation conditions, epidemics were a constant threat.

There was also the shortage of food. The agricultural factories in Australia were far from sufficient to satisfy the needs of the population, and it was necessary to transport food from across the world. As the population on the continent increased, the distribution of food became more complex and subject to more delays.

But the greatest danger was the prospect of loss of social order. In the resettlement zones, the hyper-information society disappeared. Newcomers poked the walls, bedside stands, or even their own clothes until they realized that everything was dead, un-networked. Even basic communications could not be guaranteed. People could obtain news about the world only through very limited channels. For a population used to a super-networked world full of information, it was as if they had all gone blind. Modern governments lost all their techniques for mass communication and leadership, and were ignorant of how to maintain order in a massively overcrowded society.

Simultaneously, resettlement was also proceeding in space.

At the end of the Deterrence Era, about 1.5 million people were living in space. About half a million spacers belonged to Earth International, living in space stations and space cities orbiting the Earth and bases on the moon. The rest belonged to the Solar System Fleet and were distributed between bases on Mars and around Jupiter, as well as warships patrolling the Solar System.

The spacers who belonged to Earth International mostly lived below the orbit of the moon. They had no choice but to return to the Earth and migrate to Australia.

The rest moved to the Martian base, which Trisolaris had designated as the second human reservation.

After the Doomsday Battle, the Solar System Fleet had never returned to its former size. Even at the end of the Deterrence Era, the fleet had barely more than one hundred stellar-class warships. Though technology had continued to improve, the maximum speed of the ships never increased, as fusion propulsion had already been pushed to the limit. The overwhelming advantage the Trisolar ships held was not only their ability to reach lightspeed, but, more terrifyingly, their ability to leap into lightspeed without a prolonged process of acceleration. In order to reach even 15 percent of lightspeed, human ships had to accelerate for a year, taking into account fuel consumption rates and the need to reserve fuel for the return voyage. Compared to Trisolaran ships, Earth ships were slow as snails.

When deterrence was dismantled, the stellar-class warships of the Solar System Fleet had a chance to escape into deep space. If the hundred-plus ships had sped away from the Solar System in different directions at maximum power, the eight droplets in the Solar System could not have caught them all. But not a single ship chose to do so; all obeyed Sophon and returned to Mars orbit. The reason for their obedience was simple: Resettlement on Mars was not like settling in Australia on Earth. Within the sealed habitat of the Martian base, a population of one million could maintain a comfortable, civilized existence. The base had been designed to accommodate the long-term needs of such a population. This was, without a doubt, superior to wandering deep space for the rest of their lives.

Trisolaris remained very wary of the humans on Mars. The two droplets recalled from the Kuiper Belt spent most of their time patrolling the space above the Martian city. Unlike the resettlement process on the surface of the Earth, although the Solar System Fleet had essentially been disarmed, people living on Mars still had access to modern technology—required for maintaining the habitability of the city. But the people living on Mars dared not engage in any adventures such as building a gravitational wave transmitter. The sophons certainly would have detected a large-scale venture like that, and people hadn’t forgotten the terror of the Doomsday Battle. The Martian base was as fragile as an eggshell, and the depressurization caused by a single droplet impact would have meant complete disaster.

The space resettlement process was completed in three months. Other than the Martian base, there was no more human presence in space in the Solar System, save for empty cities and ships drifting in orbit around the Earth, Mars, Jupiter, and through the asteroid belt. They seemed to form a silent, metallic graveyard, where humankind’s glory and dreams were buried.

From the safety of Fraisse’s house, Cheng Xin could only find out the situation in the larger world through TV. One day, she saw a live broadcast from a food distribution center. The holographic broadcast made her feel as if she were right there. The technology required ultra-broadband connections and was reserved for extremely important news these days. Most news was broadcast via simple 2-D.

The distribution center was located in Carnegie, on the edge of the desert. A gigantic tent appeared in the holographic display, like a broken half of an egg dropped in the desert with people spilling out of it like albumen. The crowd was rushing out because a new shipment of food had just arrived. Two flying transports, small but powerful, dangled a huge cube of packed food in nets.

After the first transport gently set down its cargo, the crowd surged like a flood from a burst dam and quickly overwhelmed the food pile. The security barrier formed by a few dozen soldiers collapsed at once, and the few food distribution workers climbed back into the hovering transport in terror. The pile of food disappeared into the crowd like a snowball thrown into muddy waters.

The lens zoomed in. People were now snatching food from those who had grabbed it from the pile. The bags of food, like rice grains in a swarm of ants, were quickly torn apart, and the mob fought over whatever tumbled out. The second transport deposited another pile in an empty space a bit farther away. This time, there were no soldiers to provide security at all, and the distribution workers didn’t dare get out of the plane. The crowd swarmed this new pile like iron shavings toward a magnet and quickly covered it.

A figure in green, slender and supple, leapt out of the transport and gracefully landed on the food pile about a dozen meters below. The crowd stopped. They saw that the figure standing atop it was Sophon. She was still dressed in camouflage, and the black scarf around her neck flapped in the hot wind, highlighting her pale face.

“Form a line!” Sophon shouted.

The lens zoomed in again. Sophon’s beautiful eyes glared at the crowd. Her voice was very loud and could be heard over the rumbling of the transport engines. But the crowd below only paused briefly before resuming their agitated motion. Those closest to the pile began to cut through the netting to get at the food bags inside. The crowd became more frenzied, and a few daring ones began to climb up the pile, ignoring Sophon.

“You useless things! Why aren’t you out here keeping order?” Sophon lifted her face and shouted at the transport. In the open door of the transport stood a few shocked officials from the UN Resettlement Commission. “Where are your armies? Your police? What about the weapons we allowed you to bring here? Where is your responsibility?”

The chair of the Resettlement Commission stood at the door of the transport. He held on to the doorframe with one hand for support, and waved his other hand at Sophon, shaking his head helplessly.

Sophon unsheathed her katana. Moving faster than the eye could see, she swung it three times and sliced three of the men climbing up the pile into six pieces. The three killing strokes were exactly the same: beginning at the left shoulder and ending at the right hip. The six pieces fell, and the viscera spilled out midair to land with a shower of blood among the rest of the people. Amidst screams of terror, she leapt from the pile and landed with her sword swinging, quickly killing more than a dozen individuals around her. The refugees shied away from her as though a drop of detergent had been deposited into the oil film over a dirty bowl, quickly clearing out a space around her. The bodies left behind in that empty space were also split from the left shoulder to the right hip, a method that guaranteed the maximum spilling of organs and blood.

Faced with so much gore and blood, many fainted. As Sophon walked forward, people hurried to back away. An invisible force field seemed to surround her, repelling the mob and keeping the space around her clear. She stopped after a few steps and the crowd froze.

“Form a line,” Sophon said. Her voice was soft.

The chaotic mob quickly organized itself into a long, winding line, as though the people were enacting an array-sorting algorithm. The line extended to the gigantic tent and wound around it.

Sophon jumped back onto the pile and pointed at the line with her bloody katana. “The era for humanity’s degenerate freedom is over. If you want to survive here, you must relearn collectivism and retrieve the dignity of your race!”

Cheng Xin couldn’t sleep that night. Noiselessly, she stepped out of her room.

The hour was late, and she could see a flickering light on the steps of the porch: Fraisse was smoking. On his knees lay a didgeridoo, an Aboriginal instrument made from a thick, hollowed-out branch about a meter long. Every night, he played it for a while. The sound made by the didgeridoo was a deep, rich, rumbling whine, not like music, but more akin to the snores of the ground itself. Every night, AA and Cheng Xin fell asleep listening to it.

Cheng Xin sat down next to Fraisse. She liked being with the old man. His transcendence in the face of a miserable reality soothed the pain of her broken heart. He never watched TV and seemed to pay no attention to the events of the outside world. At night, he rarely returned to his room, but fell asleep leaning against the doorframe, waking up when the rising sun warmed his body. He did so even on stormy nights, saying that it was more comfortable than sleeping in a bed. Once, he said that if the government bastards ever came to take away his house, he would not move to the resettlement zones; instead, he would go into the woods and build himself a shelter out of woven grass. AA said that with his advanced age, such a plan was not realistic, but he countered that if his ancestors could live that way, then so could he. As early as the fourth ice age, his ancestors had crossed the Pacific from Asia in canoes. That had been forty thousand years ago, when Greece and Egypt didn’t even exist as ideas. Back in the twenty-first century, he had been a wealthy doctor, with his own clinic in Melbourne. After emerging from hibernation in the Deterrence Era, he had also lived the comfortable life of a modern man. But when the Great Resettlement began, something in his body seemed to awaken. He felt himself becoming a creature of the earth and the forest and realized that very few things were truly necessary for life. Sleeping in the open was fine—very comfortable, in fact.

Fraisse said he didn’t know what kind of portent this was.

Cheng Xin gazed at the resettlement zone in the distance. This late at night, the lights were sparse, and the endless rows of shelter-houses gave off a rarely-seen tranquility. A strange feeling seized her, as though she were seeing another age of immigration, the Australia of five centuries ago. The people sleeping in those houses were rough cowboys and ranchers, and she could even smell the fragrance of hay and the odor of horse excrement. Cheng Xin told Fraisse of the odd sensation.

“It wasn’t so crowded back then,” said Fraisse. “They say that if a white man wanted to buy land from another white man, he needed only to pay the price of a box of whiskey, and then he would ride out with the sunrise and return at sunset. The area he circumnavigated would belong to him.”

Cheng Xin’s past impressions of Australia had come from that old film of the same name. In the film, the hero and heroine crossed the spectacular landscape of north Australia on a cattle drive. However, the film wasn’t set during Australia’s age of immigration, but during the Second World War—still the recent past when she was a young woman, but now ancient history. She felt a pang of sorrow as she realized that Hugh Jackman and Nicole Kidman had both been dead for probably over two centuries. Then she thought about how Wade had resembled the movie’s hero as he labored in the shelter-house.

Thinking of Wade, she repeated to Fraisse what the man had told her. She had been meaning to tell him, but had worried about disturbing his transcendent state of mind.

“I know the man,” Fraisse said. “Child, I can tell you that you should listen to him. But leaving Australia is impossible. Don’t worry about it. It’s useless to ponder what cannot be done.”

It was true. Leaving Australia now would be very difficult. Not only did the droplets keep watch, but Sophon had recruited her own naval force of humans. Any aircraft or surface ship leaving Australia that was found to harbor resettled individuals would be attacked immediately. In addition, as Sophon’s deadline approached, few wanted to attempt to return to their home countries. Though conditions in Australia were harsh, staying here was better than going back to certain death. A few cases of small-scale smuggling happened here and there, but Cheng Xin was a public figure, and such a path was closed to her.

Cheng Xin did not concern herself with these details. No matter what happened, she wasn’t going to leave.

Fraisse seemed to want to change the topic, but Cheng Xin’s silence in the darkness demanded more from him. “I’m an orthopedist. You probably know that when a bone is broken, it heals stronger because a knot forms around the fracture. The body, when given an opportunity to make up for an absence, may do so excessively, and recover to the point where it has more of that quality than those who had never suffered such inadequacy.” He pointed up at the sky. “Compared to humans, the Trisolarans once lacked something. Do you think they also overcompensated? To what extent? No one knows.”

Cheng Xin was stunned by the idea. But Fraisse was not interested in continuing the discussion. He looked up at the star-studded sky and began reciting poetry in a low voice. The poems spoke of dreams of long ago, of broken trust and shattered weapons, of the deaths of peoples and ways of life.

Cheng Xin was moved the same way she had been when Fraisse played the didgeridoo.

“That’s the work of Jack Davis, an Aboriginal poet of the twentieth century.”

The elder leaned against the doorframe and, after a few minutes, began to snore. Cheng Xin remained sitting under the stars—which did not deviate one whit from their usual course despite the upheaval in the world below—until dawn arrived in the east.

Six months after the commencement of the Great Resettlement, half of the world’s population, or 2.1 billion people, had moved to Australia.

Buried crises began to come to the forefront. The Canberra Massacre, seven months after the commencement of resettlement, was just the beginning of a string of nightmares.

Sophon had demanded that humans resettle “naked.” During the Deterrence Era, hardliners on Earth had also proposed a similar policy to deal with the eventual migration of Trisolarans to the Solar System. Other than construction materials and parts needed to build new agricultural factories, as well as medical equipment and other life necessities, the resettled population was not permitted to bring any heavy equipment for military or civilian use. The military forces dispatched by the various nations to the resettlement zones were only allowed the light weapons needed to maintain order. Humankind was to be completely disarmed.

But the Australian government was exempt—it was allowed to keep everything, including all the hardware for its army, navy, and air force. Thus, this country that had been on the periphery of international affairs since its birth became the hegemon of the world.

No one could find fault with the behavior of the Australian government near the beginning of the process. The government and all Australians made every effort to help with the influx of migrants. But as the flood of refugees from around the world poured into Australia, attitudes in this country—which was once the only state to possess an entire continent—changed. Native Australians complained bitterly, and they elected a new government that took a hard-line position against the newcomers. Those in the new government quickly discovered that their advantage over the rest of the world was comparable to the advantage Trisolaris held over the Earth. Late-arriving migrants were resettled in the desolate interior, whereas rich, desirable locations such as coastal New South Wales were “reserved territories” for Australians only. Canberra and Sydney were classified as “reserved cities,” where immigration was similarly prohibited. The only large city in which migrants were permitted to settle was Melbourne. The Australian government also turned dictatorial toward the rest of the world, treating itself as superior to the UN and other national governments.

Although newcomers were not allowed to settle in New South Wales, it was impossible to prevent them from going there as tourists. Many migrants swarmed to Sydney in order to assuage their intense longing for city life—even if they couldn’t stay, wandering the streets of Sydney homeless felt better than living in the resettlement zones. Here, at least, they felt they were still in civilized society. Sydney soon became overcrowded, and the Australian government decided to forcibly remove all migrants and bar them from visiting there. The police and army clashed with refugees who tarried in the city, and there were casualties.

The Sydney Incident set off the pent-up rage of the resettled population against the Australian government, and more than one hundred million people entered New South Wales, heading for Sydney. Facing a sea of rioting humanity, the Australian Army abandoned their positions. Tens of millions flooded Sydney and looted it in the same manner a swarm of ants devours a fresh corpse, leaving behind only a bare skeleton. Sydney was left in flames and lawless, transformed into a forest of terror. Life there, for those who remained, became worse than in the resettlement zones.

Thereafter, the mob of refugees shifted their target to Canberra, about two hundred kilometers away. Since Canberra was the Australian capital, about half of the world’s national governments had relocated there as well. Even the UN had just moved there from Sydney. To keep these governments safe, the army had no choice but to fire on the mob. More than half a million people were killed, most of whom didn’t die at the hands of the Australian Army, but due to hunger, thirst, and the panicked stampede of a hundred million people. During the chaos that lasted more than ten days, tens of millions were completely cut off from food and potable water.

The society of resettled populations transformed in profound ways. People realized that, on this crowded, hungry continent, democracy was more terrifying than despotism. Everyone yearned for order and a strong government. The existing social order broke down. All the people cared about was that the government would bring them food, water, and enough space for a bed; nothing else mattered. Gradually, the society of the resettled succumbed to the seduction of totalitarianism, like the surface of a lake caught in a cold spell. Sophon’s words after she killed those people at the food distribution center—“The era for humanity’s degenerate freedom is over”—became a common slogan, and discarded dregs from the history of ideas, including fascism, crawled out of their tombs to the surface and became mainstream. The power of religions also recovered, and people gathered into different faiths and churches. Thus, theocracy, a zombie even more ancient than totalitarianism, reanimated itself.

War was the inevitable result of totalitarian politics. Conflicts between nations became more frequent. At first, the conflicts were over food and water, but they soon evolved to planned contests over living space. After the Canberra Massacre, the Australian armed forces became a powerful deterrent force within Resettlement International. At the request of the UN, the Australian Army began to maintain international order by force. Without them, an intra-Australia version of a world war would have erupted—and just as someone had predicted during the twentieth century, this one would be fought with sticks and stones. By this time, the armies of the various nations—Australia excepted—couldn’t even manage to equip their personnel with mêlée weapons. The most common weapons were sticks made out of metal frames used for construction, and even ancient swords from museums were put into service again.

In those dark days, countless people woke up in the mornings incredulous that this was their reality. Within half a year, human society had regressed so far that one foot was already in the Middle Ages.

The only thing that prevented individuals and society as a whole from total collapse was the approaching Second Trisolaran Fleet. By now, the fleet had crossed the Kuiper Belt. On clear nights, it was even sometimes possible to see the flames of the decelerating ships with the naked eye. Upon those 415 dim lights now hung the hope of all of humanity. All recalled Sophon’s promise and dreamed that the arrival of the fleet would bring a comfortable, serene life for everyone on this continent. A demon of the past transformed into an angel of salvation, and their only spiritual support. People prayed for their advent.

As the resettlement process continued, cities on continents outside of Australia fell dark one by one, turning into empty, silent shells. It was like a luxurious restaurant turning out the lights after the last diner had left.

By the ninth month of the Great Resettlement, 3.4 billion people lived in Australia. As living conditions continued to deteriorate, the resettlement process had to be halted temporarily. The droplets again attacked cities outside of Australia, and Sophon renewed her threat: Upon the expiration of the one-year period, the extermination of all humans outside of the reservations would begin immediately. Australia now resembled a prison cart heading down a road to a place it would never return from: The cage was already close to bursting from the number of captives aboard, but seven hundred million more still had to be packed in.

Sophon gave some thought to the difficulties posed by further immigration and proposed a solution: New Zealand and other nearby islands could be used as a buffer zone. Her suggestion worked, and during the next two and a half months, 630 million more refugees were moved into Australia via the buffer zone.

Finally, three days before the expiration of the deadline, the last three million refugees left New Zealand on boats and planes and headed for Australia.

The Great Resettlement was complete.

At this point, Australia held the vast majority of the human population: 4.16 billion people. Outside of Australia, there were about eight million more individuals. These were divided into three parts: one million on the Martian base, five million in the Earth Security Force, and about two million in the Earth Resistance Movement. A small number of individuals who couldn’t be resettled for various reasons were scattered around the world, but their exact number was unknown.

Sophon had recruited the Earth Security Force to monitor the resettlement process. She promised those who joined that they would not have to migrate to Australia and could eventually live freely in the Trisolaris-conquered territories of the Earth. Many volunteered eagerly, and, according to the final tally, more than a billion people applied online. Of these, twenty million were offered interviews, and, in the end, five million were accepted into the ESF. These fortunate few paid no attention to the spittle and looks of disdain thrown their way by other humans—they knew that many of those who spat at them had submitted applications as well.

Some compared the Earth Security Force to the Earth-Trisolaris Organization from three centuries ago, but the two organizations were fundamentally different. The ETO was formed by warriors of faith, but the ESF recruits merely wanted to avoid resettlement and live in comfort.

The ESF was divided into three corps: Asian, European, and North American. They inherited all the military hardware the national armies were forced to leave behind during the resettlement. At the beginning of the process, the ESF behaved with some restraint, only following Sophon’s orders to supervise the progress of emigration in various countries and protect the basic infrastructure in cities and regions from looting and sabotage. But as difficulties in Australia intensified, the resettlement failed to progress at a rate satisfactory to Sophon. Due to her constant demands and threats, the ESF became more crazed, and resorted to large-scale violence to enforce the resettlement. During this time, the ESF killed almost a million people. Finally, after the clock ran out on the resettlement period, Sophon gave the order to exterminate all humans outside of the reservations. The ESF now turned into demons. Riding flying cars and armed with laser sniper rifles, they soared over empty cities and fields like falcons and swooped down to kill anyone they saw.

In contrast, the Earth Resistance Movement represented the best of humanity, refined from the furnace of this disaster. This movement consisted of so many loose local branches that the exact number couldn’t be verified. In total, an estimated one and a half to two million individuals participated. Hidden in remote mountains and deep tunnels beneath the cities, they waged guerrilla war against the ESF and waited for a chance to fight the final war against the Trisolaran invaders after their anticipated arrival in four years. Compared to all other resistance movements in human history, the Earth Resistance Movement doubtless made the greatest sacrifice. Because Sophon and the droplets assisted the ESF, every mission by the Earth Resistance Movement was akin to suicide. The conditions under which they fought also prevented them from pooling their forces, which made it possible for the ESF to eliminate them one cell at a time.

The composition of the Earth Resistance Movement was complex, and included individuals from all strata of society. A large portion were people from the Common Era. The six other candidates for the Swordholder position were all commanders in the resistance. At the end of the resettlement period, three of them had died in action: only Bi Yunfeng, the particle accelerator engineer, Cao Bing, the physicist, and Ivan Antonov, the former Russian vice-admiral, were left.

Every member of the resistance understood that they were engaged in a hopeless war. The moment the Second Trisolaran Fleet arrived would mark their complete annihilation. Hungry, dressed in rags, and hidden in caves in the mountains and sewers beneath cities, these warriors fought for the human race’s final shred of dignity. Their existence was the only bright spot in this, the darkest period of humankind’s history.

A series of booming rumbles awoke Cheng Xin at dawn. She hadn’t slept well during the night due to the constant noise of newly arrived refugees outside. But she realized that it was no longer thunderstorm season, and, after the rumblings it grew quiet outside. She shivered, rolled out of bed, threw on her clothes, and came outside. She almost tripped over the sleeping figure of Fraisse at the door. He glanced up at her with sleepy eyes and then leaned back against the doorframe to continue his interrupted slumber.

It was barely light outside. Many people stood around anxiously looking toward the east and muttering amongst themselves. Cheng Xin followed the direction of their eyes and saw a thick column of black smoke on the horizon, as though the pale dawn had been ripped apart.

Cheng Xin eventually managed to learn from the others that, about an hour ago, the ESF had begun a series of aerial raids in Australia. Their main targets seemed to be electrical systems, harbors, and large-scale transportation equipment. The column of smoke came from a destroyed nuclear fusion power plant about five kilometers away. People looked up in fear and saw five white contrails extending across the blue-black sky: ESF bombers.

Cheng Xin went back into the house. AA was up as well and turned on the TV. But Cheng Xin didn’t watch—she didn’t need any more information. For almost a year now, she had been constantly praying that this moment would never come. Her nerves had turned extremely sensitive, and the slightest hint would lead her to the right conclusion. Even as she had been awakened by the rumbling noises, she already knew what had happened.

Wade was right, again.

Cheng Xin found that she was prepared for this moment. Without thinking, she knew what she had to do. Telling AA that she needed to visit the city government, she took a bike—the most convenient mode of transportation in the resettlement zones. She also brought some food and water, knowing that she very likely would not be able to accomplish her task and would have to be on the road for a long time.

She wound through the crowded streets, heading for the city government. The various nations had transplanted their own administrative systems to the resettlement zones, and Cheng Xin’s zone was composed of people resettled from a midsized city in northwestern China. The city government was located in a large tent about two kilometers away, and she could see the tent’s white tip.

A large number of refugees had flooded in during the last two weeks in the final push of the resettlement process. There was no time to distribute them to zones that corresponded to their origins, so they were stashed wherever there was room. Cheng Xin’s zone was thus filled with people from other cities, regions, provinces, and even non-Chinese. The seven hundred million refugees shoved into Australia during the last two months made the already-crowded resettlement zones even more unbearable.

On both sides of the road, possessions were piled everywhere. The new arrivals had nowhere to live and slept in the open. The earlier explosions had awakened them, and now they looked anxiously in the direction of the column of smoke. The dawn light cast a dim blue glow over everything, making the faces around her even paler. Once again, Cheng Xin experienced the eerie feeling of looking down upon an ant colony. As she pressed between the pale faces, her subconscious mind despaired that the sun would never rise again.

A wave of nausea and weakness seized her. She squeezed the brakes, stopped by the side of the road, and retched, bringing tears to her eyes. She dry heaved until her stomach settled. She heard a child crying nearby, and looking up, saw a mother huddled in a bunch of rags hugging her baby. Haggard, hair disheveled, she didn’t move as the child clutched at her, but continued to gaze woodenly toward the east. The dawn lit her eyes, which reflected only loss and numbness.

Cheng Xin thought of another mother, pretty, healthy, and full of life, handing her baby to Cheng Xin in front of the UN building… where were she and her child now?

As she approached the tent housing the city government, Cheng Xin was forced to get off her bike and squeeze through the dense crowd. This place was always crowded, but now, even more people had gathered to find out what had happened. Cheng Xin had to explain who she was to the sentry line blocking the entrance before being allowed through. The officer didn’t know her and had to scan her ID card. When he confirmed her identity, his stare seared itself into Cheng Xin’s memory.

Why did we pick you back then?

The inside of the city government tent brought back memories of the hyper-information age. Numerous holographic windows floated around the vast space, hovering over various officials and clerks. Many of them had apparently been up all night and looked exhausted, but they were still very busy. A large number of departments were packed in and jostled for space, reminding Cheng Xin of the trading floor on Wall Street back in the Common Era. The workers tapped or wrote inside the windows hovering in front of them, and then the windows automatically floated over to the next worker in the process. These glowing windows were like ghosts of an age that had just ended, and here was their final gathering place.

In a tiny office formed from composite partitions, Cheng Xin saw the mayor. He was very young, and his feminized, handsome face looked as exhausted as the others. He also looked a bit dazed and adrift, as though the load he had been given was beyond the ability of his fragile generation to bear. A very large information window appeared on one of the walls, showing an image of some city. Most of the buildings in the window looked old and conventional, with only a few tree-buildings sprinkled among them—evidently this was a midsized city. Cheng Xin noticed that the image wasn’t static: Flying cars crossed the air from time to time, and it seemed to also be early morning there. Cheng Xin realized that the display simulated the view out of an office window, so perhaps this was where the mayor had once lived and worked before the Great Resettlement.

He looked at Cheng Xin, and his eyes also seemed to say Why did we pick you? Still, he remained polite, and asked Cheng Xin how he could help her.

“I need to contact Sophon,” she said.

The mayor shook his head, but her unexpected request had chased away some of his exhaustion. He looked serious. “That’s not possible. First, this department is too low level to directly establish contact with her. Even the provincial government doesn’t have such authority. No one knows where on Earth she is now. Also, communication with the outside world is extremely difficult now. We’ve just been cut off from the provincial government, and we’re about to lose electricity here.”

“Can you send me to Canberra?”

“I can’t provide an aircraft, but I can dispatch a ground vehicle. However, that may end up being even slower than walking. Ms. Cheng, I strongly urge you to stay put. There’s chaos everywhere right now, and it’s very dangerous. The cities are being bombed—believe it or not, it’s relatively peaceful here.”

Since there was no wireless power system, flying cars were not usable in the resettlement zones. Only self-powered aircraft and ground vehicles were available, but the roads had become impassable.

As soon as Cheng Xin left the city government, she heard another explosion. A new column of smoke rose in another direction, and the crowd turned from merely anxious to genuinely agitated. She pushed her way through and found her bike. She would have to ride more than fifty kilometers to reach the provincial government and try to contact Sophon from there. If that didn’t work, she’d try to get to Canberra.

No matter what, she would not give up.

The crowd quieted as an immense information window appeared over the city government, almost as wide as the tent itself. This was used only when the government needed to broadcast extremely important news. Since the electric voltage wasn’t stable, the window flickered, but against the dim sky of early dawn, it showed images very clearly.

In the window was Canberra’s Parliament House. Though it was completed in 1988, people still referred to it as the “new” Parliament House. From a distance, the building appeared as a bunker nestled against a hill, and on top of it was possibly the world’s tallest flag mast. The mast, over eighty meters in height, was further elevated by four gigantic steel beams. They were meant to symbolize stability, but they now resembled the frame of a large tent. The UN flag flew from the building: The UN had moved its headquarters here after the Sydney Riots.

Cheng Xin felt a giant fist close around her heart. She knew that the day of the Last Judgment had arrived.

The view shifted to inside the House of Representatives, which was filled by all the leaders of Earth International and Fleet International. Sophon had called for an emergency session of the UN General Assembly.

Sophon stood at the dispatch box, still dressed in camouflage and a black scarf, but without the katana. There was no trace on her face of the glamorous cruelty that everyone had grown used to in the past year; instead, she appeared radiant in her beauty. She bowed to the assembled leaders of humanity, and Cheng Xin saw again the gentle hostess practicing the Way of Tea whom she had met two years ago.

“The Great Resettlement is over!” Sophon bowed again. “Thank you! I’m grateful to all of you. This is a tremendous accomplishment, comparable to the walk out of Africa by your ancestors tens of thousands of years ago. A new era for our two civilizations has begun!”

Everyone in the House of Representatives turned their head anxiously as something exploded outside. The four lighting beams hanging from the ceiling swayed, and all the shadows along with them, as though the building was about to collapse. But Sophon continued speaking: “Before the magnificent Trisolaran Fleet arrives to bring you a happy new life, everyone must endure a difficult period lasting three months. I hope humanity will perform as well as it did during the Great Resettlement.

“I proclaim now the complete severance of the Australian Reservation from the outside world. Seven strong-interaction space probes and the Earth Security Force will enforce an absolute blockade. Anyone attempting to leave Australia will be treated as an invader of Trisolaris and be exterminated without mercy!

“The defanging of Earth must proceed. During the next three months, the reservation must be kept in a state of subsistence agriculture. The use of any modern technology, including electricity, is strictly prohibited. As everyone present can see, the Earth Security Force is in the process of systematically eliminating all electricity-generating equipment in Australia.”

People around Cheng Xin looked at each other in disbelief, hoping that someone else could help explain what Sophon had just said.

“This is genocide!” someone in the House of Representatives cried out. The shadows continued to sway, like corpses dangling from nooses.

It was indeed genocide.

The prospect of keeping 4.2 billion people alive in Australia was difficult, but not unimaginable. Even after the Great Resettlement, the population density in Australia was only fifty people per square kilometer, lower than the population density of pre-Resettlement Japan.

But the plan had been premised on highly efficient agricultural factories. During the resettlement process, large numbers of agricultural factories had been relocated to Australia, and many of them had been reassembled and put in operation. In these factories, genetically modified crops grew at rates orders of magnitude above traditional crops, but natural lighting was insufficient to power such growth, so ultrabright artificial lights had to be used. This required massive amounts of electricity.

Without electricity, the crops in the growth tanks of the factories, dependent on ultraviolet or X-ray light for photosynthesis, would rot in a couple of days.

The existing food reserve was enough to maintain 4.2 billion people only for one month.

“I don’t understand your reaction,” Sophon said to the man who had yelled genocide. Her confusion appeared genuine.

“What about food? Where are we going to get food?” someone else shouted. They were no longer terrified of Sophon. All that was left was despair.

Sophon scanned the hall, meeting the eyes of everyone present. “Food? Everyone, look around: You are surrounded by food, living food.”

Her tone was serene, as though reminding humanity of a storehouse they had forgotten.

No one said anything. The long-planned process of annihilation had reached its final step. It was too late for words.

Sophon continued. “The coming struggle for survival will eliminate most of humanity. By the time the fleet arrives in three months, there should be about thirty to fifty million people left on this continent. These final victors will begin a free and civilized life in the reservation. The fire of Earth civilization will not go out, but it will continue in a reduced form, like the eternal flame at a tomb.”

The Australian House of Representatives was modeled on the British House of Commons. The high seats of the public galleries were to the sides, and the benches for the Members of Parliament—where the leaders of the world now sat—were down in the pit in the middle. Those sitting there now felt as if they were in a tomb that was about to be filled in.

“Mere existence is already the result of incredible luck. Such was the case on Earth in the past, and such has always been the case in this cruel universe. But at some point, humanity began to develop the illusion that they’re entitled to life, that life can be taken for granted. This is the fundamental reason for your defeat. The flag of evolution will be raised once again on this world, and you will now fight for your survival. I hope everyone present will be among the fifty million survivors at the end. I hope that you will eat food, and not be eaten by food.”

“Ahhhhhhh—” A woman in the crowd near Cheng Xin screamed, slicing apart the silence like a sharp blade. But a deathlike hush immediately swallowed her scream.

Cheng Xin felt the sky and earth tumble around her. She didn’t realize she had fallen down. All she saw was the sky pushing the government tent and the holographic window away, filling her entire field of view, then the ground touched her back, as though it had stood up behind her. The dawn sky appeared as a dim ocean, and the crimson clouds, lit by the rising sun, floated over it in bloody patches. Then a black spot appeared in her vision, spreading quickly, like a sheet of paper set aflame by the candle underneath, until murky shadows covered everything.

She recovered from the loss of consciousness quickly. Her hands found the ground—soft sand—and, pushing off it, she sat up. She grabbed her left arm with her right hand to be sure that she was okay. But the world had disappeared. All was enveloped in gloom. Cheng Xin opened her eyes wide, but she could see nothing but more darkness. She had gone blind.

Noises assaulted her; she could not tell which were real and which were illusions: footsteps like a tide, screams, sobs, and indistinct, eerie cries like a gale passing through a dead forest.

Someone running crashed into her, and she fell. She struggled to sit up. Darkness, only darkness remained before her eyes, thick as pitch. She turned to face what she thought of as the east, but even in her mind she couldn’t see the rising sun. What rose there instead was a gigantic dark wheel, scattering black light across the world.

In this endless obscurity she seemed to see a pair of eyes. The black eyes melted into the murk, but she could feel their presence, could feel their gaze. Were these the eyes of Yun Tianming? She had fallen into the abyss, where she ought to meet him. She heard Tianming call her name. She tried to push the hallucinatory voice out of her mind, but it persisted. Finally, she was certain that the voice came from reality, as it was a feminized male voice that could only be from this era.

“Are you Dr. Cheng Xin?”

She nodded. Or, rather, felt herself nod. Her body seemed to move on its own.

“What happened to your eyes? Can you not see?”

“Who are you?”

“I’m the commander of a special team in the Earth Security Force. Sophon sent us to retrieve you from Australia.”

“Where are you taking me?”

“Anywhere you want. She’ll take care of you. Of course, she said that you have to be willing to go.”

Cheng Xin noticed another sound. She thought it was another hallucination at first: the rumbling of a helicopter. Although humanity had learned anti-gravity technology, it consumed too much energy for practical use. Aircraft still mostly relied on traditional propellers. She felt gusts of wind, proof that a helicopter was hovering nearby.

“Can I talk to Sophon?”

An object was pushed into her hand—a mobile phone. She put the phone next to her ear and heard Sophon’s voice.

“Hello, Swordholder.”

“I’ve been looking for you.”

“Why? Do you still think of yourself as the savior of the world?”

Cheng Xin shook her head slowly. “No. I’ve never thought of myself that way. I just want to save two people. Please?”

“Which two?”

“艾 AA and Fraisse.”

“Ah, your chattering friend and that old Aboriginal? You wanted to find me just for this?”

Cheng Xin was surprised. Sophon had met AA, but how did she know who Fraisse was?

“Yes. Have the people you sent bring them away from Australia so that they can live freely.”

“That’s easy. What about you?”

“You don’t need to be concerned about me.”

“Can’t you see what’s happening?”

“I can’t. I can’t see a thing.”

“You mean you’ve gone blind? Haven’t you been eating properly?”

Cheng Xin, AA, and Fraisse had always been provided adequate rations during the last year, and Fraisse’s house had never been taken away by the government. And once she and AA had moved in, no one had harassed her. Cheng Xin had always thought it was because the local government was protecting her, but now she realized that it was because Sophon had kept watch over her.

Cheng Xin understood that it was a group of aliens that controlled Sophon from four light-years away, but she, like other humans, always thought of Sophon as an individual, a woman. This woman, who was in the process of slaughtering 4.2 billion people, cared about her welfare.

“If you remain there, you’ll be eaten by the others.”

“I know.” Cheng Xin’s voice was calm.

Is that a sigh? “All right. A sophon will stay near you. If you change your mind or need some help, just speak. I’ll hear you.”

Cheng Xin said nothing. Not even thank you.

Someone grabbed her by the arm—the Earth Security Force commander. “I’ve been given the order to retrieve those two. It’s best that you leave with us, Dr. Cheng. This place will turn into hell on Earth in no time.”

Cheng Xin shook her head. “You know where they are? Good. Please go. Thank you.”

She listened for the helicopter. The blindness seemed to make her hearing especially acute, like a third eye. She heard the helicopter take off and then land about two kilometers away. A few minutes later, it lifted off again, and gradually flew away.

Cheng Xin closed her eyes, satisfied. Whether she kept them open or not, there was only darkness. Finally, her broken heart had found some peace, bathed in a pool of blood. The impenetrable shadows now became a kind of protection. Outside the darkness was more terror. What had manifested there made even coldness itself shiver, even darkness itself stumble.

The frenzy around her intensified: sounds of running, clashing, guns firing, cursing, screaming, dying, crying… Have they already started to eat people? It shouldn’t happen so fast. Cheng Xin believed that even in a month, when there would be no more food, most people would still refuse to eat other people.

That’s why most people will die.

It was not important whether the fifty million that survived would still be considered human, or become something else. As a concept, “humanity” would disappear.

A single line could now encompass all of human history: We walked out of Africa; we walked for seventy thousand years; we came into Australia.

In Australia, humanity returned to its origin. But there would be no new voyage. This was the end.

A baby cried nearby. Cheng Xin wanted to wrap her arms around that new life. She recalled the baby she had held in front of the UN building: soft, warm, such a sweet smile. Maternal instinct broke Cheng Xin’s heart. She was afraid that the baby would go hungry.

The Final Ten Minutes of the Deterrence Era, Year 62 November 28, 4:17:34 P.M. to 4:27:58 P.M.: Gravity and Blue Space, Deep Space

When the klaxons announced the droplet attack, only one man aboard Gravity felt a sense of relief: James Hunter, the oldest on the crew. He was seventy-eight, and everyone called him Old Hunter.

Half a century ago, at Fleet Command in Jupiter’s orbit, a twenty-seven-year-old Hunter had received his mission from the chief of staff.

“You will be the culinary controller aboard Gravity.”

This position was just a glorified name for the ship’s cook. But since AI programming did most of the cooking on a warship, the culinary controller was responsible only for operating the system. This meant, for the most part, inputting the menu for each meal and choosing the staples. Most culinary controllers were petty officers, but Hunter had just been promoted to the rank of captain; in fact, he was the youngest captain in the fleet. But Hunter wasn’t surprised. He knew what he was really supposed to do.

“Your real mission is to guard the gravitational wave transmitter. If the senior officers aboard Gravity lose control of the ship, you must destroy the transmitter. In unexpected situations, you may use whatever means you deem necessary to accomplish your goal.”

Gravity’s gravitational wave broadcasting system included the antenna and the controller. The antenna was the ship’s hull, impossible to destroy, but disabling the controller was enough to stop transmission. Given the materials available on Gravity and Blue Space, it would be impossible to assemble a new controller.

Hunter knew that men similar to himself had served on nuclear submarines in ancient times. Back then, in the ballistic missile submarine fleets of both the Soviet Union and NATO, there were seamen and low-ranked officers serving in humble posts who also had such missions. If anyone had come close to seizing control of a submarine and the missiles it carried, these men would have emerged, unexpectedly, to take drastic action to stop such plots.

“You must pay attention to everything happening on the ship. Your mission requires you to monitor the situation during every duty cycle. Thus, you cannot hibernate.”

“I don’t know if I can live until I’m a hundred.”

“You only need to live until you’re eighty. By then, the degenerate matter vibrating string in the ship will have reached its half-life, Gravity’s gravitational wave transmission system will fail, and you’ll have completed your mission. Thus, you just need to stay out of hibernation for the voyage out, but may return asleep. However, the mission will essentially require you to devote the rest of your life to it. You have the right to refuse.”

“I accept.”

The chief of staff asked a question that commanders in past eras would not have bothered with. “Why?”

“During the Doomsday Battle, I was a PIA intelligence analyst stationed aboard Newton. Before the droplet destroyed my ship, I escaped in a life pod. Though it was the smallest kind of life pod, it was capable of holding five. At the time, a group of my crewmates were headed toward me, and I was alone in my pod. But I released it—”

“I know about that. The court-martial results are unequivocal. You did nothing wrong. Ten seconds after jettisoning your life pod, the ship exploded. You had no time to wait for anyone else.”

“Yes. But… I still feel it would have been better if I had stayed with Newton.”

“I understand how our failures haunt us with survivor’s guilt. But this time, you have a chance to save billions.”

The two were silent for a while. Outside the window of the space station, the Great Red Spot of Jupiter stared at them like a gigantic eye.

“Before I explain to you the details of your task, I want you to understand one thing: Your highest priority is preventing the system from falling into the wrong hands. When you cannot ascertain the degree of risk with confidence, you should err on the side of destroying the transmission system—even if you should turn out to be mistaken. When you do decide to act, don’t worry about collateral damage. If necessary, destroying the entire ship would be acceptable.”

Hunter was in the first duty cycle when Gravity left Earth. During those five years, he regularly took a certain kind of small blue pills. At the end of the duty cycle, when he was scheduled to go into hibernation, a physical revealed that he had cerebrovascular coagulation disorder, which was also called “no-hibernation disease.” Patients with this rare condition suffered no ill effects in daily life, but could not enter hibernation because the awakening process would cause massive brain damage. It was the only medical condition discovered so far that could prevent someone from going into hibernation. When the diagnosis was confirmed, everyone around Hunter looked at him as though they were at his funeral.

Thus, throughout the whole voyage, Hunter had remained awake. Every time someone emerged from hibernation, they saw he had aged more. He told all the newly awakened the interesting things that had happened in the dozen or so years that had passed while they slept. The lowly cook became the most beloved figure on the ship, and he was popular with officers and enlisted men alike. Gradually, he turned into a symbol of the long voyage of Gravity. No one suspected that this easygoing, generous man held the same rank as the captain and was also the only man other than the captain with the authority and ability to destroy the ship in the event of a crisis.

During the first thirty years of the journey, Hunter had several girlfriends. In this matter he held an advantage others did not possess: He could date women in different duty cycles, one after the other. But after a few decades, as Hunter became Old Hunter, the women, still young, treated him as only a friend with interesting stories.

During this half century, the only woman Old Hunter ever truly loved was Reiko Akihara. But most of that time, more than ten million AU separated them. This was because Sublieutenant Akihara was aboard Blue Space, where she was a navigator.

The hunt for Blue Space was the only undertaking where Earth and Trisolaris truly shared the same goal, because this lone ship heading into deep space was a threat to both worlds. During the Earth’s attempt to lure back the two ships that had survived the dark battles, Blue Space had learned the dark forest nature of the universe. If Blue Space someday mastered the ability to broadcast to the universe, the consequences would be unimaginable. The hunt thus received the total cooperation of Trisolaris. Before entering the blind region, the sophons had provided Gravity with a real-time, continuous view of the interior of the prey.

Over the decades, Hunter was promoted from petty officer second class to petty officer first class, and then, as a special promotion, became a commissioned officer. Starting as an ensign, he was promoted all the way up to lieutenant. But even at the end, he never had the formal authorization to view the live feed of the interior of Blue Space transmitted by the sophons. However, he did possess the backdoor codes to all the ship’s systems, and he often viewed a palm-sized version of the video feed in his own cabin.

He saw that Blue Space was a completely different society from Gravity. It was militaristic, authoritarian, and governed by strict codes of discipline. Everyone devoted their spiritual energy to the collective. The first time he saw Reiko was two years after the start of the chase. He was instantly smitten by this East Asian beauty. He would watch her for hours every day, and sometimes even thought he knew her life better than he knew his own. But a year later, Reiko went into hibernation, and the next time she woke up for duty was thirty years later. She was still young, but Hunter was already near sixty.

On Christmas Eve, after a wild party, he returned to his cabin and brought up the live feed from Blue Space. The view began with a diagram of the complex overall structure of the ship. He tapped the location of the navigation center, and the view zoomed in to show Reiko on duty. She was looking at a large holographic star map, on which a bright red line traced the course of Blue Space. Behind it was a white line that almost coincided with the red line, indicating the path taken by Gravity. Hunter noticed that the white line deviated slightly from Gravity’s true course. Right now, the two ships were still a few thousand AU apart. At this distance, it was difficult to track a target as small as a spaceship with certainty. The white line probably only indicated their best guess, although the estimate of the distance between the two ships was pretty accurate.

Hunter zoomed in some more. Reiko suddenly turned to face him, and, with a smile that made his heart clench, said, “Merry Christmas!” Hunter knew that Reiko wasn’t talking to him, but to all those hunting her ship. She was aware that she was being watched by sophons, though she couldn’t see her pursuers. Regardless, this was one of the happiest moments of Hunter’s life.

Because the crew aboard Blue Space was large, Reiko’s duty cycle didn’t last long. One year later, she entered hibernation again. Hunter looked forward to the day he would meet Reiko face-to-face, when Gravity finally caught up to Blue Space. Sadly, he knew that he would be almost eighty by the time that happened. He hoped he would get to tell her he loved her and then watch as she was taken away for trial.

For half a century, Hunter faithfully carried out his mission. He remained alert for any unusual conditions aboard the ship, preparing in his mind action plans for various crises. But the mission didn’t really put too much pressure on him. He knew that another form of insurance, utterly reliable, accompanied Gravity. Like many others, he often watched the droplets cruising at a distance from the portholes. But the droplets, in his eyes, held another meaning. If anything unusual occurred on Gravity, especially if there were signs of a mutiny or illegal attempts to seize control of the gravitational wave transmission system, he knew that the droplets would destroy this ship. They could move far faster than he—a droplet could accelerate from a few thousand meters away and reach a target in no more than five seconds.

Now, Hunter’s mission was almost over. The degenerate matter vibrating string at the heart of the gravitational wave antenna, less than ten nanometers in diameter but running the entire length of the fifteen-hundred-meter hull, had almost reached its half-life. In another two months, the density of the string would fall below the minimum threshold for gravitational wave transmissions, and the system would fail completely. Gravity would turn from a broadcast station that posed a threat to two worlds to an ordinary stellar spaceship, and Hunter’s work would be done. He would reveal his true identity at that time. He was curious whether he would face admiration or condemnation from his crewmates. In any case, he would stop taking those blue pills, and his cerebrovascular coagulation disorder would disappear. He would enter hibernation and awaken on the Earth to live out the rest of his days in a new era. But he would hibernate only after seeing Reiko, which should happen soon.

But then the sophons fell blind. During the voyage, he had imagined hundreds of possible crises, and this was one of the worst possibilities. The loss of the sophons meant that the droplets and Trisolaris no longer knew everything happening aboard Gravity. If the unexpected happened, the droplets could not react in time. This made the situation far more dangerous, and Hunter felt the weight on his shoulders increase tenfold, as though he had only started his mission.

Hunter now paid even closer attention to happenings on the ship. The entire crew of Gravity had been awakened from hibernation, and that made monitoring difficult. But Hunter was the only member of the crew everyone was familiar with, and he was popular and had an abundance of social connections. Moreover, his easygoing manner and his insignificant post meant that most were not on guard in his presence. The enlisted men and junior officers, especially, told him things they wouldn’t dare say to senior officers or the psych corps. This allowed Hunter to have a full grasp of the situation.

After the sophons were blinded, strange things began to happen all over the ship: An ecological area in the middle of the ship was struck by a micrometeoroid; more than one person claimed to have seen openings suddenly appear in bulkheads, accompanied by the disappearance of certain objects that reappeared later, undamaged….

Out of all these oddities, the experience of Commander Devon, head of the MP, made the deepest impression on Hunter. Devon was one of the senior officers on the ship. Normally Hunter did not interact with them much. But when he saw Devon seek out the psychiatrist—whom most people on the ship avoided—he grew alert. Over a bottle of vintage whiskey, he finally got Devon to spill the story of his strange encounter.

To be sure, other than the micrometeoroid strike, the most reasonable explanation for all the strange goings-on was that the crew was suffering from hallucinations. The loss of the sophons might have, in some unknown way, triggered a kind of mass mental disorder—at least that was how Dr. West and the psych corps explained it. Hunter’s duty did not allow him to accept this explanation easily; but other than hallucinations or a mass mental disorder, the strange stories told by the crew seemed impossible. However, Hunter’s mission was to respond to impossibilities that somehow became possible.

Despite the massive antenna, the controller unit for the gravitational wave transmitter took up little space. Situated in a small spherical cabin at the stern, the controller was completely independent and not connected to the other parts of the ship. The spherical cabin was like a reinforced safe. No one aboard Gravity had the codes for entry, not even the captain. Only the Swordholder on Earth could activate the gravitational wave broadcast—in such an event, a beam of neutrinos would be transmitted to Gravity and switch on the transmitter. Right now, such a signal would take a year to arrive from the Earth.

But if Gravity were hijacked, the safety measures around the spherical cabin would not last long.

Hunter’s watch had a special button. When pressed, it would trigger a heat bomb inside the spherical cabin, which would vaporize everything inside. His job was very simple: No matter what the crisis, as soon as he judged the risk to be in excess of a certain threshold, he would press the button and destroy the controller, rendering the gravitational wave transmitter inoperable.

In a sense, Hunter was an “Anti-Swordholder.”

Hunter didn’t put all his trust in the button on his watch and the heat bomb in the cabin, which he had never laid eyes on. Ideally, he wanted to keep watch outside the control cabin day and night, but of course that would draw suspicion, and his hidden identity was his biggest advantage. Still, he wanted to be as close to the control cabin as possible, so he tried to regularly visit the astronomical observatory, also located at the stern. Since the entire crew was out of hibernation, Hunter had assistants to take care of his culinary duties, which gave him plenty of time to himself. In addition, as Dr. Guan Yifan was the only civilian scientist aboard and thus not subject to military discipline, no one thought it strange that Hunter often went to Guan to share the liquor that he was able to obtain due to his position. Dr. Guan, in turn, enjoyed the drinks, and lectured Hunter on the “universe’s three and three hundred thousand syndrome.” Soon, Hunter spent most of his time in the observatory, separated from the gravitational wave transmission controller by only a short corridor about twenty meters long.

Hunter was on his way to the observatory again when he passed Guan Yifan and Dr. West heading for the bow of the ship. He decided that he would take a peek at the control cabin. When he was about ten meters away, the klaxons for the droplet attack started blaring. Due to his rank, the information window appearing before him displayed very few details, but he knew that the droplets were, at this time, farther away from the ship than when they had flown in formation. He had about ten to twenty seconds until impact.

During these final moments, Old Hunter felt only relief and joy. No matter what happened next, he would have completed his mission. He looked forward not to death, but to his victory.

This was why, half a minute later, when the klaxons stopped, Hunter became the only one aboard who felt no relief from his extreme terror. The cessation of the alarm indicated, for him, great danger: In a situation of great uncertainty, the gravitational wave transmitter was still intact. Without hesitation, he pressed the button on his watch.

Nothing happened. Even though the control cabin was tightly sealed, he should have been able to feel the tremors from the detonation. A line of text appeared on his wristwatch display:

Failure: The self-destruct module has been dismantled.

Hunter wasn’t even surprised. He had already intuitively anticipated that the worst had happened. He had been but a few seconds from relief, but the relief would never come.

Neither droplet struck their respective targets. Both brushed by Gravity or Blue Space at extremely close range—only a few tens of meters.

Three minutes after the attack alert was lifted, Joseph Morovich, captain of Gravity, finally managed to gather his senior staff at the combat center, in the middle of which was a giant situation map. No stars were shown against the dark expanse of space, only the positions of the two ships and the attack trajectories of the droplets. The two long white trails appeared as straight lines, but the data indicated they were parabolas with very low curvature. As the two droplets accelerated toward their targets in the simulation, their headings began to drift. The changes were small, but cumulatively, they resulted in the droplets barely missing their targets. Many of the senior officers had participated in the Doomsday Battle, and their memory of the sharp turns the droplets were capable of executing while moving at extremely high velocities still brought heart-stopping terror. However, the trajectories on the display were completely different: It was as though some outside force perpendicular to the attack vectors of the droplets had steadily pushed them out of the way.

“Replay the recording,” the captain ordered. “Visible light range.”

The stars and the galaxy appeared. This was no longer a computer simulation. In one corner, flickering numbers showed the passage of time. Everyone relived the terror of a few minutes ago, when all they could do was wait for death because evasive maneuvers and defensive shots were all meaningless. Soon, the numbers stopped changing. The droplets had already swept past the ships, but because they were moving so fast, no one could see them.

The display shifted to slow-motion replay of the high-speed recording. Since the complete recording, over ten seconds long, would take a long time to play through, only the last few seconds were shown. The officers saw a droplet pass in front of the camera like a faint meteor across the sea of stars in the background. The recording was played again, and froze when the droplet was in the middle of the screen. The image zoomed in until the droplet took up most of the display.

Half a century of cruising in formation with the droplets made everyone familiar with their appearance, and what they saw now shocked them. The droplet on the display was still shaped like a teardrop, but its surface was no longer a perfectly smooth mirror. Instead, it was dim and coppery yellow, as though full of rust. It was as if a magician’s spell of eternal youth had failed, and the marks left by three centuries of spaceflight had all appeared at once. Instead of a shining spirit, the droplet had turned into an ancient artillery shell drifting through space. Communications with the Earth during the last few years had given these officers some basic insight into the principles of strong-interaction materials. They knew that the surface of a droplet was held in a force field generated by mechanisms inside. This force field counteracted the electromagnetic force between particles, allowing the strong nuclear force to spill out. Without the force field, strong-interaction material reverted to ordinary metal.

The droplets had died.

Next, they reviewed the post-attack data. The simulation showed that after the droplet brushed by Gravity, the mysterious perpendicular force making small heading changes vanished, and the droplet coasted along its final vector. But this only lasted a few seconds. Thereafter, the droplet began to decelerate. The combat analysis computer concluded that the force decelerating the droplet was equal in magnitude to the force that had changed its heading. The obvious conclusion was that the source of the force had shifted from pushing at the side of the droplet to pushing from the front.

Since the recording was made by high-magnification telescopic lens, it was possible to see the back of the departing droplet. The droplet turned ninety degrees so that it was perpendicular to its own direction of motion and continued to coast. Then it began to decelerate. The next scene seemed to be taken from a fairy tale—good thing Dr. West was also present, or else he would again declare the others to be suffering from hallucinations. A triangular object, about twice as long as the droplet, appeared in front of it. The staff immediately recognized it as a shuttle from Blue Space! In order to increase its propulsive power, multiple small fusion drives were attached to the hull of the shuttle. Although the nozzles of the drives all pointed away from the camera, it was still possible to see the glow they made as they operated under maximum output. The shuttle was pushing against the droplet to slow it down. And it was easy to deduce that it was also the source of the force that caused the droplets to deviate from their attack vectors.

After the shuttle’s appearance, two human figures wearing space suits appeared on the other side of the droplet—the side closest to the camera. The deceleration caused the figures to stick to the surface of the droplet; one of them held some kind of instrument in his hands and appeared to be analyzing the droplet. In the past, droplets had seemed almost divine in the eyes of humankind, not belonging to this world and not approachable. The only people who had ever come close to touching a droplet had been vaporized in the Doomsday Battle. But now, the droplet had lost all its mystery. Without its mirrorlike sheen, it seemed ordinary, broken-down, older and less advanced than the shuttle and the astronauts—some antique or piece of trash collected by the latter. A few seconds later, the shuttle and the astronauts disappeared, and the dead droplet was once again alone in space. But it continued to decelerate, indicating that the shuttle was still there pushing against it, only now invisible.

“They know how to disable the droplets!” someone cried out.

Captain Morovich could think of only one thing. Like Hunter a few minutes ago, he didn’t hesitate to push the button on his watch. The error message appeared in a red information window that appeared midair:

Failure: The self-destruct module has been dismantled.

The captain dashed out of the combat center and headed for the stern. The other officers followed.

The first person from Gravity to arrive at the gravitational wave transmission control room was Old Hunter. Though he had no authorization to enter the cabin, he wanted to try to break the link between the controller and the antenna. This would at least temporarily disable the transmission system until he figured out how to destroy the controller itself.

But someone was already there, examining the control cabin.

Hunter took out his sidearm and aimed it at the man. He wore the uniform of a sublieutenant on Gravity, not the uniform dating from the Doomsday Battle that Hunter expected to see—the man had stolen it. Hunter recognized him from the back. “I knew Commander Devon was right.”

Lieutenant Commander Park Ui-gun, head of the marines on Blue Space, turned around. He looked no older than thirty, but his face showed that he had endured experiences that no one aboard Gravity could imagine. He was slightly surprised. Perhaps he didn’t expect anyone here so soon; perhaps he didn’t expect to see Hunter. Yet, he remained calm. With both hands half raised, he said, “Please let me explain—”

Old Hunter wasn’t interested in an explanation. He didn’t want to know how this man had boarded Gravity, and didn’t even want to know if he was a man or a ghost. Whatever the facts, the situation was too dangerous. All he wanted was to destroy the transmission controller unit. It was his only goal in life, and this man from Blue Space stood in the way. He squeezed the trigger.

The bullet struck Park in the chest, and the impact threw him against the cabin door. Hunter’s gun was loaded with special bullets designed for use inside the ship: They wouldn’t damage the bulkheads or other equipment, but they also weren’t as deadly as laser beams. Some blood oozed out of the wound, but Park managed to stay erect in the weightlessness and reached into his bloody uniform for his own weapon. Hunter shot again, and there was a fresh wound in Park’s chest. More blood oozed out, floating in the gravity-less air. Finally, Hunter took aim at Park’s head, but he didn’t get a chance for the third shot.

This was the scene that greeted Captain Morovich and the other officers when they arrived: Hunter’s gun was floating far away from him. The old cook’s body was stiff, his open eyes showing only white, his limbs twitching. Blood erupted forth from his mouth like a fountain, coagulating into spheres of various sizes drifting around him in a cloud. In the middle of the bloody, translucent spheres was a dark red object about the size of a fist, dragging two tubes behind it like tails.

Rhythmically, it pulsed in midair, and with every pulse, more blood was squeezed out of its two tubular tails. The object propelled itself forward like a crimson jellyfish swimming through the air.

It was Hunter’s heart.

During the struggle a few moments earlier, Hunter had slammed his right hand against his chest, and then, desperately, torn open his clothes. Thus, his bare chest lay revealed, and everyone could see that the skin was perfect, with not a single scratch.

“He can be saved if we get him into surgery right away,” Sublieutenant Park said with some difficulty, his voice very hoarse. Blood continued to spill from the two wounds in his chest. “Good thing that doctors don’t need to open his chest to reattach his heart anymore…. Don’t move! It’s as easy for them to pluck out your heart or brain as it is for you to pick an apple dangling from a branch in front of you. Gravity has been captured.”

Fully armed marines rushed in from another corridor. Most of them wore the dark blue lightweight space suits dating from before the Doomsday Battle—apparently they were all from Blue Space. All the marines were equipped with powerful laser assault rifles.

Captain Morovich nodded at his officers. Without speaking, they tossed their weapons away. Blue Space had ten times more people than Gravity, and just their detachment of marines numbered more than a hundred. They could easily control Gravity.

There was nothing beyond belief anymore. Blue Space had turned into a supernatural warship wielding magic. The crew of Gravity again experienced the shock they had last suffered during the Doomsday Battle.

More than fourteen hundred people floated in the middle of Blue Space’s spherical great hall. The largest portion, over twelve hundred, belonged to the crew of Blue Space. Sixty years ago, the officers and enlisted men of this ship had also lined up here to accept Zhang Beihai’s command, and most of them were still here. Since only a few individuals needed to be awake and on duty for regular cruising, the crew had aged only three to five years on average. They hadn’t experienced the bulk of the intervening years, and the searing flames of the dark battles and the cold funerals held in space remained fresh in their minds. The remainder belonged to the one-hundred-strong crew of Gravity. The two crews—one large, one small, wearing distinct uniforms and suspicious of each other—gathered into two clusters far apart from each other.

Before the two crews, the senior officers of the two ships were mixed together. Captain Chu Yan of Blue Space drew the most attention. He was forty-three, but looked younger, and he was the model of the scholarly military officer. Refined and calm in his speech and mannerisms, he even gave off a hint of shyness. But on Earth, Chu Yan was already a figure of legend. During the dark battles, he was the one who had given the order to turn the interior of Blue Space into a vacuum, thereby preventing the crew from death in the infrasonic nuclear bomb attack. Even now, public opinion on Earth remained divided as to whether Blue Space’s actions during the dark battle should be classified as self-defense or murder. After the founding of dark forest deterrence, he was the one who had resisted the heavy pressure of majority opinion aboard and delayed Blue Space’s return, thus giving the ship sufficient time to escape after the warning from Bronze Age. There were many other rumors concerning Chu Yan. For instance, when Natural Selection had chosen to defect and escape the Doomsday Battle, he was the only captain to ask to give chase. Some claimed that he had a different purpose in mind, wanting to hijack Blue Space and escape along with Natural Selection. Of course, those were just rumors.

“Almost everyone from the two ships is gathered here,” said Chu Yan. “Although much still divides us, we prefer to think of everyone as belonging to the same world, formed from Blue Space and Gravity. Before we plan the future of our world together, we need to take care of an urgent matter.”

A large holographic display window appeared midair, showing somewhere in space where the stars were sparse. In the middle of the region was a faint white fog, and the fog was etched with several hundred straight parallel lines, like brush bristles. The white lines had clearly been enhanced and stood out in the image. In the past two centuries, these “brushes” had become very familiar to people, and some brands even used them in their logos.

“These trails were observed eight days ago in the stellar dust cloud near Trisolaris. Please pay attention to the video.”

Everyone stared at the image, and the trails could be seen to grow in the fog.

“How many times have you sped up the video?” an officer from Gravity asked.

“It’s not sped up at all.”

The crowd grew agitated, like a forest struck by a sudden rainstorm.

“By a rough estimate… these ships are moving at close to the speed of light,” Captain Morovich of Gravity said. His voice was very tranquil. He had experienced too many incredible sights in the last two days.

“That’s right. The Second Trisolaran Fleet is heading for Earth at lightspeed, and should arrive in four years.” Chu Yan looked at Gravity’s crew with caring eyes, as though sorry that he had to deliver this news. “After you left, the Earth sank into a dream of universal peace and prosperity, and completely misjudged the situation. Trisolaris has been waiting patiently, and now they’ve finally seized their chance.”

“How do we know this is authentic?” someone from Gravity called out.

“I can attest to it!” said Guan Yifan. Among the small gathering in front of the crews, he was the only one not in a military uniform. “My observatory had also detected the same trails. However, since I was focused on large-scale cosmological observations, I didn’t pay much attention to them. But I’ve gone back and retrieved the recorded data. The Solar System, the Trisolaran system, and our ships form a scalene triangle. The side between the Solar System and the Trisolaran system is the longest. The side between the Solar System and us is the shortest. The side going from the Trisolaran system to us is in between. In other words, we are closer to the Trisolaran system than the Solar System is to the Trisolaran system. About forty days from now, the Earth will also detect the trails we’re seeing.”

Chu Yan took over. “We believe that something has already taken place on the Earth. More specifically, it happened about five hours ago, when the droplets attacked our two ships. Based on information provided by Gravity, that was the scheduled time for the Swordholder to transfer his authority to his successor. This was the opportunity Trisolaris had been waiting for for half a century. The two droplets had clearly been given orders before entering the blind zone. This was a long-planned, coordinated attack.

“I must conclude that the peace brought by dark forest deterrence has been breached. There are only two possibilities: The gravitational wave universal broadcast has been initiated, or it hasn’t.”

Chu Yan tapped in the air and brought up Cheng Xin’s picture on the holographic display. This picture of the new Swordholder had also just been obtained from Gravity. Cheng Xin stood in front of the UN Secretariat Building, holding a baby. Her picture had been blown up to be as large as the “brush” bristles, and the contrast between the two images couldn’t be sharper. The basic color scheme of space was black and silver—the depth of space and the cold light of the stars. But Cheng Xin resembled a Madonna from the East. A warm, golden glow bathed her and the baby, giving all those present the feeling of being close to the sun, a sensation that they had missed for half a century.

“We believe the latter scenario is true,” Chu Yan said.

“How did they pick such a person to be Swordholder?” someone from Blue Space asked.

Captain Morovich answered. “It’s been sixty years since you left home, and fifty for us. Everything on Earth has changed. Deterrence made a comfortable cradle, and as humanity napped inside, it regressed from an adult to a child.”

“Don’t you know that there are no more men on Earth?” someone from Gravity shouted.

“Humans on Earth lost the ability to maintain dark forest deterrence,” Chu Yan said. “We had planned to capture Gravity and re-establish dark forest deterrence. But we’ve just found out that due to decay in the antenna, the ability to broadcast gravitational waves will only last two more months. Believe me, this has been an incredible blow to all of us. We have only one choice: immediately activate the universal broadcast.”

The crowd erupted. Next to the view of cold space showing the lightspeed trails of the Trisolaran Fleet, Cheng Xin gazed at them, full of love. The two images portrayed their two choices.

“Are you really willing to commit mundicide?” Captain Morovich demanded.

Chu Yan maintained his serenity against the chaos. Ignoring Captain Morovich, he spoke to the crowd. “For us, initiating the broadcast is meaningless. Neither the Earth nor Trisolaris can catch us now.”

Everyone understood this. The sophons were permanently severed from home, and the droplets had been destroyed. Earth and Trisolaris thus had no way to trace them. In the vast, deep space beyond the Oort Cloud, even Trisolaran ships operating at lightspeed would never be able to find two motes of dust.

“Then you’re just seeking revenge!” an officer from Gravity said.

“Vengeance against Trisolaris is our right. They must pay for the crimes they’ve committed. In war, it is right and just to destroy one’s enemies. If my deduction is correct, humankind’s gravitational wave transmitters have all been destroyed, and the Earth is now under occupation. It’s very likely that the genocide of the human race is underway.

“Activating the universal broadcast would give the Earth one last chance. If the location of the Solar System is revealed, it would no longer have any value to Trisolaris because it could be destroyed at any moment. This would force the Trisolarans to leave the Solar System, and their lightspeed fleet would have to turn away. We may be able to save the human race from immediate annihilation. To give them more time, our broadcast will include only the location of Trisolaris.”

“That’s the same as revealing the Solar System! It’s too close.”

“We all know that, but hopefully this will give the Earth a little more time and allow more humans to escape. Whether they will choose to do so is up to them.”

“You’re talking about destroying two worlds!” said Captain Morovich. “And one of them is our mother. This decision is the Last Judgment. It cannot be made so lightly.”

“I agree.”

A holographic rectangular red button about a meter long appeared between the two existing information windows. Below it was a number: 0.

Chu Yan continued. “As I said earlier: together, we are one world. Everyone in this world is an ordinary person, but fate has put us into the position of making the last judgment about two worlds. This decision must be made, but a single person or even a few persons shouldn’t make it. This will be the decision of the whole world through a referendum. All in favor of broadcasting the location of Trisolaris to the universe, please press this red button. All opposed or abstaining, do nothing.

“Right now, the total number of people aboard Blue Space and Gravity, including all present and those on duty, is one thousand four hundred and fifteen. If the ayes reach or exceed two-thirds of the total, nine hundred forty-four, the universal broadcast will begin immediately. Otherwise, we will never activate the broadcast and let the antenna decay and fail.

“Begin.”

Chu Yan turned and pressed the giant red button hovering in air. The button flashed, and the number below it turned from 0 to 1. Next, the two vice-captains of Blue Space pressed the buttons in quick succession. The tally went up to 3. Then the other senior officers of Blue Space, followed by the junior officers and enlisted men, filed past the red button in a long line, pressing the button again and again.

As the red button flashed, the tally crept up. These were the final beats of the heart of history, the final steps taken toward the terminal point.

When the number reached 795, Guan Yifan pressed the button. He was the first person from Gravity to support the broadcast. After him, several more officers and enlisted men from Gravity also pressed the button.

Finally, the number reached 943, and a large line of text appeared above the button:

The next affirmative vote will activate the universal broadcast.

The next person to vote was an enlisted man. Many others were lined up behind him. He placed his hand above the button, but didn’t push. He waited until the ensign behind him put his hand on his, and then more hands joined theirs in a thick stack.

“Please wait,” Captain Morovich said. He drifted over and, as everyone watched, placed his hand atop the pile.

Then dozens of hands moved together, and the button flashed one more time.

Three hundred fifteen years had passed since that morning in the twentieth century when Ye Wenjie had pushed another red button.

The gravitational wave broadcast began. Everyone present felt a strong tremor. The feeling seemed to come not from without, but from within each body, as though every person had become a vibrating string. This instrument of death played for only twelve seconds before stopping, and then everything was silent.

Outside the ship, the thin membrane of space-time rippled with the gravitational waves, like a placid lake surface disturbed by a night breeze. The judgment of death for both worlds spread across the cosmos at the speed of light.

Post-Deterrence Era, Year 2 The Morning After the Great Resettlement, Australia

The noises around her quieted down, and Cheng Xin could hear voices coming from the information window over the city government tent. She could tell one of the voices belonged to Sophon, in addition to two others. But she was too far away to make out exactly what they said. She thought their voices cast a spell because the noises around her faded and finally disappeared. The world seemed to be frozen.

Then a tsunami erupted around her, and Cheng Xin trembled. She had been blind for a while, and the images of the real world in her mind were being squeezed out bit by bit by illusions. The sudden bedlam made her feel as if the Pacific had risen up all around her and swallowed Australia.

It took a few seconds before she understood that the crowd was cheering. What’s there to cheer about? Has everyone gone mad? The clamor did not subside, though it was eventually replaced by speech. So many were talking at once it was as if, after the continent had been flooded, a storm lashed the surface of the sea. She could not tell what anyone was saying in the tumult.

But she picked out “Blue Space” and “Gravity” more than once.

Her hearing gradually recovered its acuity, and she noticed a faint sound amidst the general commotion: footsteps in front of her. She felt someone stop there.

“Dr. Cheng Xin, what is wrong with your eyes? Can you not see?” Cheng Xin felt movements disturbing the air. Perhaps the man was waving his hands before her eyes. “The mayor sent me for you. We’re going home, back to China.”

“I don’t have a home,” Cheng Xin said. The word “home” stabbed into her heart like a knife, and her heart, numbed by extreme pain, nevertheless convulsed one more time. She thought of that winter night three centuries ago when she left her home, thought of the dawn that had greeted her outside her window…. Both of her parents had died before the Great Ravine. They could never have imagined where their daughter had ended up, tempest-tossed by time and fate.

“No. Everyone’s getting ready to go home. We’re all leaving Australia and going back to where we came from.”

Cheng Xin whipped her head up. She still couldn’t get used to this stubborn darkness before her wide-open eyes. She tried to make out something, anything. “What?”

“Gravity initiated the universal broadcast.”

How is that possible?

“The location of Trisolaris has been exposed—which of course means the Solar System is exposed as well. The Trisolarans are running away. The Second Fleet has changed direction to head away from the Solar System. All the droplets are gone. Sophon was explaining that there’s no more need to worry about them invading the Solar System. Like the Trisolaran system, this is now a place of death that everyone will want to escape from.”

How!?

“We’re going home. Sophon has ordered the Earth Security Force to make every effort to assist with the evacuation of Australia. The process will get faster over time, but moving all the refugees out of Australia will take three to six months. You can leave first. The mayor wants me to take you to the provincial government.”

“Was it Blue Space?”

“No one knows the details, not even Sophon. But Trisolaris received the universal broadcast, and it was initiated a year ago, when deterrence failed.”

“Can you let me be by myself for a while?”

“All right, Dr. Cheng. But you should be happy. They did what you needed to do.”

The man stopped talking, but Cheng Xin could still feel his presence. The commotion around her gradually died down, and was followed by a rainstorm of footsteps. The footsteps grew sparse—everyone must be leaving the city government tent to take care of their own business. Cheng Xin felt the sea retreat around her, revealing solid land beneath. She stood in the middle of an empty continent, the sole survivor after the Flood. Her face felt a trace of warmth: The sun was rising.

Post-Deterrence Era, Day 1–Day 5 Gravity and Blue Space, Deep Space Beyond the Oort Cloud

“It’s possible to detect the warped points using the naked eye,” Chu Yan said. “But the best way is to monitor the electromagnetic radiation. The emission from these points is very faint, but it has a distinct spectral signature. The regular sensors on our ships can detect and locate them. Typically, a volume of space as large as a ship in this region contains one to two warped points, but we once found twelve at once. Look, right now there are three.”

Chu Yan, Morovich, and Guan Yifan were floating through a long corridor on Blue Space. In front of them drifted an information window showing a map of the interior of the ship. Three red dots flashed on the map, and the three of them were approaching one of these dots now.

“Right there!” Guan pointed straight ahead.

In the bulkhead in front of them was a circular hole about a meter in diameter. The edge was smooth, mirrorlike. Through the hole they could see tubes of various thicknesses. Several tubes had entire sections missing in the middle. In two of the thicker tubes, they could see liquid flowing. The liquid seemed to flow from one section, disappear, and then reappear in the corresponding section of the tube on the other side. The missing sections were of different lengths, but overall seemed to describe a spherical space. Based on the shape of the missing sections, part of the invisible bubble protruded into the corridor. Morovich and Guan carefully avoided it.

Chu Yan carelessly extended a hand into the invisible bubble, and half of his arm disappeared. Standing to the side, Guan Yifan saw a clear cross section of his cut-off arm, like the cross sections of Vera’s legs that had been seen by Sublieutenant Ike aboard the Gravity. Chu Yan pulled his arm back and showed the astonished Morovich and Guan that it was unharmed. Then he encouraged them to try it. The two carefully reached into the invisible bubble. They watched their hands, and then arms, vanish, but they felt nothing.

“Let’s go in,” said Chu Yan. Then he jumped into the bubble, as though diving into a pool. Morovich and Guan watched in consternation as Captain Chu disappeared from head to toe. The cross section of his body on the surface of the invisible bubble rapidly changed shape, and the mirrorlike edge of the hole threw reflections onto the surrounding bulkheads like ripples.

As Morovich and Guan stared at each other, two hands and forearms emerged from the bubble and remained suspended in midair. Each hand grabbed hold of one of theirs, and they were pulled into fourth-dimensional space.

All who had experienced it agree that the sensation of being in four-dimensional space was indescribable. They would even say that it was the only thing encountered by humanity thus far that absolutely could not be captured by language.

People usually resorted to this analogy: Imagine a race of flat beings living inside a two-dimensional picture. No matter how rich or colorful the picture was, the flat people could only see the profile of the world around them. In their eyes, everything consisted of line segments of various lengths. Only when such a two-dimensional being was taken up out of the picture into three-dimensional space and looking down on the world could he see the entirety of the image.

This analogy simply expressed in some more detail the indescribability of experiencing four-dimensional space.

A person looking back upon the three-dimensional world from four-dimensional space for the first time realized this right away: He had never seen the world while he was in it. If the three-dimensional world were likened to a picture, all he had seen before was just a narrow view from the side: a line. Only from four-dimensional space could he see the picture as a whole. He would describe it this way: Nothing blocked whatever was placed behind it. Even the interiors of sealed spaces were laid open. This seemed a simple change, but when the world was displayed this way, the visual effect was utterly stunning. When all barriers and concealments were stripped away, and everything was exposed, the amount of information entering the viewer’s eyes was hundreds of millions times greater than when he was in three-dimensional space. The brain could not even process so much information right away.

In Morovich and Guan’s eyes, Blue Space was a magnificent, immense painting that had just been unrolled. They could see all the way to the stern, and all the way to the bow; they could see the inside of every cabin and every sealed container in the ship; they could see the liquid flowing through the maze of tubes, and the fiery ball of fusion in the reactor at the stern…. Of course, the rules of perspective remained in operation, and objects far away appeared indistinct, but everything was visible.

Given this description, those who had never experienced four-dimensional space might get the wrong impression that they were seeing everything “through” the hull. But no, they were not seeing “through” anything. Everything was laid out in the open, just like when we look at a circle drawn on a piece of paper, we can see the inside of the circle without looking “through” anything. This kind of openness extended to every level, and the hardest part was describing how it applied to solid objects. One could see the interior of solids, such as the bulkheads or a piece of metal or a rock—one could see all the cross sections at once! Morovich and Guan were drowning in a sea of information—all the details of the universe were gathered around them and fighting for their attention in vivid colors.

Morovich and Guan had to learn to deal with an entirely novel visual phenomenon: unlimited details. In three-dimensional space, the human visual system dealt with limited details. No matter how complicated the environment or the object, the visible elements were limited. Given enough time, it was always possible to take in most of the details one by one. But when one viewed the three-dimensional world from four-dimensional space, all concealed and hidden details were revealed simultaneously, since three-dimensional objects were laid open at every level. Take a sealed container as an example: One could see not only what was inside, but also the interiors of the objects inside. This boundless disclosure and exposure led to the unlimited details on display.

Everything in the ship lay exposed before Morovich and Guan, but even when observing some specific object, such as a cup or a pen, they saw infinite details, and the information received by their visual systems was incalculable. Even a lifetime would not be enough to take in the shape of any one of these objects in four-dimensional space. When an object was revealed at all levels in four-dimensional space, it created in the viewer a vertigo-inducing sensation of depth, like a set of Russian nesting dolls that went on without end. Bounded in a nutshell but counting oneself a king of infinite space was no longer merely a metaphor.

Morovich and Guan looked at each other, then looked at Chu Yan to the side. They saw bodies revealed at every level with the details displayed in parallel: They could see bones, organs, the marrow inside the bones, the blood flowing through the ventricles and atria of the heart, the openings and closings of the mitral and tricuspid valves. When gazing at each other, they could see clearly the interior structure of the lenses of the eyes….

The phrase “in parallel” might also lead to misunderstanding. The physical locations of the parts of the body had not been shifted around: The skin still enclosed the organs and the bones, and the familiar shape of each person in three-dimensional space persisted—but it was now merely one detail among an infinity of details, visible at the same time, in parallel.

“Be careful of where you move your hands,” Chu Yan said. “You might poke an internal organ—yours or someone else’s—by mistake. But as long as you don’t use too much force, even contact won’t be a big deal. You’ll feel a bit of pain or nausea, and of course there’s the risk of infections. Also, don’t touch or move things unless you know exactly what they are. Everything on the ship is now naked: You might be touching a live wire or heated steam, or even integrated circuits, and cause system malfunctions. Overall, you’re like gods in the three-dimensional world, but you have to get used to being in four-dimensional space before you can use your powers effectively.”

Morovich and Guan quickly learned how to avoid touching inner organs. By moving in a certain direction, they could grasp someone’s hand instead of the bones inside the hand. To touch the bones or organs required exertion in another direction—a direction that didn’t exist in three-dimensional space.

Next, Morovich and Guan discovered something else that excited them: They could see the stars in every direction. They could see the bright glow of the Milky Way extending through the universal eternal night. They knew that they were still inside the ship—none of them wore space suits, and all breathed the air on the ship—but in the fourth dimension, they were exposed to space. All three veteran spacers had performed countless spacewalks, but they had never felt so utterly intimate with space. During spacewalks, they were at least enclosed by space suits, but now, nothing stood between space and them. The ship that revealed infinite details did not shield them from space. In the fourth dimension, the ship lay in parallel with all of space.

The brain that had been adapted from birth to sense and feel three-dimensional space could not handle the infinite information generated by countless details, and initially, information overload threatened to shut down processing. But the brain soon grew used to the four-dimensional environment, and without conscious thought it learned to ignore most details, leaving only the frames around objects.

After the initial vertigo, Morovich and Guan experienced another, even greater shock. Once their attention was no longer completely absorbed by the inexhaustible details of the environment around them, they sensed space itself, or sensed the fourth dimension. Later, people would call this feeling “high-dimensional spatial sense.” For those who had experienced it, high-dimensional spatial sense was hard to convey in words. They often tried to explain it this way: Concepts like “vastness” or “boundlessness” in three-dimensional space were replicated an infinite number of times in four-dimensional space in a direction that did not exist in three-dimensional space. They often resorted to the analogy of two mirrors facing each other: In either mirror one could see a boundless multitude of replicated mirrors, a hall of mirrors that extended into infinity. In this analogy, each mirror in the hall was a three-dimensional space. In other words, the vastness that one experienced in three-dimensional space was but a cross-section of the vastness of four-dimensional space. The difficulty of describing high-dimensional spatial sense lay in the fact that for observers situated in four-dimensional space, the space they could see was empty and uniform, but there was a depth to it that could not be captured by language. This depth was not a matter of distance: It was bound up in every point in space. Guan Yifan’s exclamation later became a classic quote:

“A bottomless abyss exists in every inch.”

The experience of high-dimensional spatial sense was a spiritual baptism. In one moment, concepts like freedom, openness, profundity, and infinity all gained brand-new meanings.

Chu Yan said, “We should return. The warped points remain stable for only a brief period of time before drifting away or disappearing. To find a new warped point requires moving in four-dimensional space. That’s a dangerous undertaking for novices like you.”

“How does one find a warped point in four-dimensional space?” Morovich asked.

“Simple. A warped point is usually spherical. Light is refracted inside the sphere, and objects inside are distorted, causing a visual break in the image of the objects. Of course, this is just an optical effect in four-dimensional space, not a real change in the shapes of the objects. Look over there—”

Chu Yan pointed in the direction they had come from. Morovich and Guan saw those tubes again, which now also lay open so that all the liquids flowing through them could be seen clearly. Inside the spherical region, the tubes were curved and distorted, and the sphere appeared like a drop of dew hanging on a spiderweb. This was different from how the region had appeared in three-dimensional space. There, the warped point didn’t refract light, and so appeared completely invisible. Its presence could only be made known via the disappearance of objects that had entered four-dimensional space inside the bubble.

“If you come here again, you must wear space suits. Novices can’t always tell locations accurately, and finding a new warped point for the return trip might result in landing outside the ship in three-dimensional space.”

Chu Yan indicated that the other two should follow, and entered the dewdrop-like bubble. In an instant they were back inside the three-dimensional world, back in the corridor inside the ship, in exactly the place where, ten minutes ago, they had entered four-dimensional space. In fact, they had never left—the space they were in had just gained an extra dimension. The round opening in the bulkhead was still there, and they could still see the “broken” tubes inside.

But to Morovich and Guan, the world no longer seemed familiar. They now experienced the three-dimensional world as narrow and smothering. Guan dealt with it slightly better—he had at least experienced four-dimensional space once before, in a semiconscious state. But Morovich was feeling claustrophobic, as though he was being suffocated.

“This is normal. You’ll get used to it after a few times.” Chu Yan laughed. “The two of you now know what real vastness means. Even if you put on space suits and go take a walk in space now, you’ll feel confined.”

“How did all this happen?” Morovich tore open his collar and gasped.

“We entered a region of space where space has four dimensions. That’s it. We call this region a four-dimensional fragment.”

“But we’re in three-dimensional space now!”

“Four-dimensional space contains three-dimensional space, just as three-dimensional space contains two-dimensional space. To make another analogy: We’re located inside a three-dimensional sheet of paper in four-dimensional space.”

“Let me propose a model,” said Guan excitedly. “The entirety of our three-dimensional space is a large, thin sheet of paper, sixteen billion light-years across. Somewhere on this sheet of paper is a tiny, four-dimensional soap bubble.”

“Perfect, Dr. Guan!” Chu Yan clapped Guan’s shoulder, making him tumble in weightlessness. “I’ve been trying to come up with a good analogy, and you hit it in one try. This is why we need a cosmologist! You’re exactly right. We were on this three-dimensional sheet of paper, crawling over the surface. Then we came into the soap bubble. From a warped point, we can manage to leave the surface of the paper and entered the space inside the bubble.”

“Though we were in four-dimensional space just now, our bodies remained three-dimensional,” Morovich said.

“That’s right. We were flat, three-dimensional people drifting in four-dimensional space. It’s not clear how our bodies are able to survive in four-dimensional space, given that the physical laws are likely different. There are many such mysteries.”

“What exactly are warped points?”

“The three-dimensional sheet of paper is not completely flat everywhere. Some places are warped, reaching into the fourth dimension. That’s what a warped point is: a tunnel from lower dimensions into higher dimensions. We can get into four-dimensional space by jumping into them.”

“Are there many warped points?”

“Oh yes. They’re everywhere. Blue Space was able to discover their secret earlier because we have more people aboard, and so there were many more opportunities to encounter warped points. Gravity, besides having fewer people, also had a much stricter psychological monitoring regime—even those who encountered warped points dared not discuss them.”

“Are all warped points this small?”

“No. Some are much bigger. There’s one mystery we’ve never been able to solve: We once observed that the rear third of Gravity had warped into four-dimensional space, and stayed there for several minutes. How could you have not noticed anything odd?”

“Well, the last third of the ship usually had no crew. Oh, wait, he was there.” Morovich turned to Guan Yifan. “You must have experienced that. I think I heard about it from Dr. West.”

“I was only half awake. Later, that idiot convinced me that I was only hallucinating.”

“It’s not possible to look into the fourth dimension from three-dimensional space. But it is possible to be in four-dimensional space and see everything happening in three-dimensional space and to affect things in it. We were able to lay an ambush against the droplets from four-dimensional space. No matter how powerful the strong-interaction probes were, they were still three-dimensional objects. In a sense, three-dimensionality is synonymous with fragility. Viewed from four-dimensional space, it was an unrolled painting, defenseless. We approached it from the fourth dimension, and, without understanding its principles of operation, sabotaged its internal mechanisms—completely exposed—at random.

“Is Trisolaris aware of the existence of the four-dimensional fragment?”

“We think not.”

“The soap bubble—uh, four-dimensional fragment—how big is it?”

“Talking about the size of four-dimensional space from three-dimensional space is kind of meaningless. We can only discuss how big the projection of the fragment is in three dimensions. Based on preliminary investigation, we think the three-dimensional projection is spherical. If that’s true, based on the data collected so far, its radius is between forty to fifty AU.”

“About the size of the Solar System.”

The round opening in the bulkhead next to the three of them began to move slowly and to shrink. When it was just over ten meters from them, the opening disappeared completely. But the information window floating near them indicated that two more warped points had appeared aboard Blue Space.

“How could a four-dimensional fragment appear in three-dimensional space?” Guan Yifan muttered to himself.

“No one knows. Doctor, this is your puzzle to solve.”

After the discovery of the four-dimensional fragment, Blue Space had explored and studied the space inside extensively. The addition of Gravity brought more advanced equipment and techniques, so the crews could conduct more comprehensive and in-depth exploration.

In three-dimensional space, this region appeared very empty and showed no irregularities. Much of the exploration had to be conducted in four-dimensional space. Since releasing probes into four-dimensional space was no trivial matter, most of the research was conducted by inserting a telescope into the fragment through a warped point. Manipulating a three-dimensional instrument in four dimensions required some practice, and a period of adjustment, but once the scientists got the hang of it, they immediately made shocking discoveries.

Through the telescope, they discovered a ring-shaped object. Since it was impossible to determine its distance from the ship, it was also impossible to estimate its size. The best guess was that its three-dimensional diameter was between eighty to one hundred kilometers, and the band of the ring was about twenty kilometers thick. The whole thing resembled a giant wedding band spinning in space. Complex patterns resembling circuitry could be discerned on the surface of the band. Based on the evidence, it seemed reasonable to conclude that the ring had been constructed by intelligent beings.

This was the first time humanity had observed another civilization outside of the Earth and Trisolaris.

But the most shocking thing was that the “Ring” was sealed. It existed in four-dimensional space, but didn’t reveal its interior as a three-dimensional object would have. Since its inside was concealed, that meant it was a true four-dimensional object. This was also the first true four-dimensional object detected by humanity since entering four-dimensional space.

People initially feared an attack, but the surface of the Ring showed no signs of any activity. They also detected no emission of any electromagnetic, neutrino, or gravitational wave signals. Other than a slow, stately revolving motion, the Ring showed no acceleration. The working theory was that this was a ruin, perhaps a long-abandoned space city or spaceship.

Further observations revealed more unknown objects in the depths of four-dimensional space. They were all sealed four-dimensional objects of different sizes and shapes, and many seemed to be artifacts fashioned by intelligence: pyramids, crosses, polyhedral frames, and so on. Other objects were irregular forms composed from simpler shapes, also clearly not natural. More than a dozen of these objects had shapes that could be discerned by telescope, though farther away were many more objects that appeared only as point sources. In total, about a hundred such objects were found. Like the Ring, none of them showed signs of activity, and they emitted no detectable signals.

Guan Yifan proposed to Captain Chu the plan of piloting a pinnace to the Ring and studying it up close. If possible, he wanted to enter the Ring. The captain denied this proposal unequivocally. Navigating through four-dimensional space was fraught with risks. To precisely fix one’s location required four coordinates, but equipment brought from three-dimensional space could only determine three coordinates. This meant three-dimensional explorers could not determine the location of any object in four-dimensional space with precision. An explorer could not ascertain the location or distance of the Ring using instrumentation or visual observation, so it would be possible to collide with the Ring at any moment.

Similarly, locating a warped point to return to three-dimensional space would be very difficult. Since the coordinate in one of the four directions could not be determined, when a warped point was found, all that was known was its direction, not its distance from the observer. The crew of the pinnace could use a warped point to return to three-dimensional space and, to their surprise, find themselves far away from Blue Space.

Finally, most of the radio waves linking Blue Space and the pinnace would spill into the fourth dimension, leading to far faster decay of signal strength and causing communication difficulties.

After that, Blue Space and Gravity suffered six micrometeoroid strikes in one day. A 140-nanometer micrometeoroid struck and completely destroyed the magnetic levitation controller of Blue Space’s fusion reactor core. This was a key system aboard the ship. The fusion reactor core could reach temperatures as high as a million degrees, which would vaporize any material it came in contact with. A magnetic field kept it centered within the reaction chamber. If the controller failed, the superheated reactor core could escape from the magnetic field and instantly destroy the ship. Fortunately, the backup unit kicked in immediately and shut off the reactor—which was operating at minimal power—and averted catastrophe.

As the two ships sailed deeper into the four-dimensional fragment, the density of micrometeoroid strikes increased, and even larger meteoroids, visible to the naked eye, passed near the ships. Their velocity relative to the ships was several times the third cosmic velocity. In three-dimensional space, the critical parts of the ships were wrapped in layers of protection, but here, they lay exposed to the fourth dimension, completely defenseless.

Chu Yan decided that the two ships should retreat from the four-dimensional fragment. The fragment as a whole was moving away from the Solar System, heading in the same direction as the ships’ course; thus, although Blue Space and Gravity were sailing away from the Solar System at a high speed, their velocity relative to the fragment was small, and they had only slowly caught up to the fragment. They weren’t deep within the fragment and should be able to decelerate and leave it easily.

Guan Yifan raged against this decision. “The greatest mystery in the universe is right in front of us. The answers to all our cosmological questions may be found here. How can we leave?”

“Are you talking about the three and three hundred thousand syndrome? The fragment did remind me of it.”

“Even if you focus only on the practical, we can probably recover unimaginable knowledge and artifacts from that ring-shaped ruin.”

“Such gains are only meaningful if we survive this ordeal. Right now, both of our ships could be annihilated any moment.”

Guan sighed and shook his head. “Fine. But before you leave, let me ride a pinnace to explore the Ring. Give me a chance. You spoke of survival, but perhaps our future survival depends on what I can discover here!”

“We can consider sending a drone.”

“In a four-dimensional world, only a live observer can understand what is seen. You know this better than I.”

After a brief discussion, the senior staff of both ships approved Guan’s proposal. Guan Yifan, Lieutenant Zhuo Wen, and Dr. West made up the exploratory team. Lieutenant Zhuo was the science officer aboard Blue Space and had comparatively extensive experience navigating in four dimensions. Dr. West, on the other hand, simply insisted that he come; the request was ultimately approved because he had studied Trisolaran language before the voyage.

Prior to this, the longest voyage in four-dimensional space had been the attack on the droplets and Gravity. During the attack, a pinnace had sailed through four-dimensional space to approach Gravity, and then three people, including Lieutenant Commander Park Ui-gun, had entered Gravity via a warped point to reconnoiter. Thereafter, more than sixty marines had boarded Gravity in three separate waves. The attack on the droplets had relied on smaller shuttles. But this voyage of discovery to the Ring would be far longer.

The pinnace entered four-dimensional space from a warped point between the two ships. At the tail of the pinnace, the small fusion reactor’s core turned from dim red to a faint blue as its power level increased. This flame, together with the balls of fire in the reactors of the two larger ships, illuminated this world of infinity times infinity. Blue Space and Gravity quickly receded, and as the pinnace sailed deeper into four-dimensional space, the high-dimensional spatial sensation intensified. Although Dr. West had already been to four-dimensional space twice, he exclaimed, “How grand is the spirit that can grasp such a world!”

Lieutenant Zhuo piloted the pinnace using voice commands or by moving the cursor with his gaze—it was a good idea to avoid using hands and risking contact with some sensitive piece of equipment that now lay exposed in four dimensions. To the naked eye, the Ring was still but a barely visible dot, but Zhuo cautiously kept the pinnace flying at a very low speed. Due to the extra unmeasurable dimension, visual judgments of distance were completely unreliable. The Ring might be as far away as an astronomical unit or as close as the pinnace’s bow.

After three hours, the pinnace had already exceeded the previous record of distance sailed from the ships in four-dimensional space. The Ring remained but a dot. Lieutenant Zhuo grew even more cautious and was prepared to decelerate at full power and to change the heading at a moment’s notice. Guan Yifan grew impatient and asked Zhuo to fly faster. Just then, West cried out in surprise.

The Ring turned into a real ring—it just happened. One moment, it was still a dot; the next moment, it was a ring the size of a coin. There was no gradual process of change at all.

“You’ve got to remember that we’re basically blind in the fourth dimension,” Lieutenant Zhuo said. He decreased their speed again.

Two more hours passed. If they were still in three-dimensional space, they would have sailed about two hundred thousand kilometers.

All of a sudden, the coin-sized Ring turned into a gigantic structure. Lieutenant Zhuo banked sharply and barely managed to avoid collision. The pinnace passed through the Ring like an arch in space. The pinnace decelerated, turned around, and came to a stop a short distance from the Ring.

This was the first time humans had come close to a four-dimensional object. Similar to high-dimensional spatial sense, they felt the magnificence of high-dimensional materiality. The Ring was completely sealed, and they could not look inside the band, but they could feel an immense sense of depth and of containment. What they were seeing wasn’t just a Ring, but an infinity of Rings all stacked together in concealment. This sensation of four-dimensionality impressed itself upon the soul, and gave the observers the experience of seeing the mountain contained in a mustard seed described in Buddhist parables.

From up close, the surface of the Ring appeared very different from images taken by the telescope. Instead of a golden yellow light, it gave off a dark copper glow. Those faint etched lines that had looked like circuitry were really lines left by micrometeoroids striking its surface. There was still no evidence of any activity, and it didn’t emit light or other radiation. Looking at the ancient surface of the Ring, all three felt a sense of familiarity. They recalled the destroyed droplets, and then tried to imagine the immense four-dimensional Ring with a mirrorlike smooth surface—it would have been a breathtaking sight.

Following the preestablished plan, Lieutenant Zhuo transmitted a message to the Ring via medium-frequency radio waves. This was a simple bitmap, a bit array that could be interpreted as six lines of dots that formed a sequence of prime numbers: 2, 3, 5, 7, 11, 13.

They weren’t expecting any answers, but an answer arrived immediately, so fast that they couldn’t believe their eyes. The information window hovering in the middle of the pinnace cabin displayed a simple bitmap similar to the one they had sent. It also consisted of six lines portraying the next six prime numbers: 17, 19, 23, 29, 31, 37.

The original plan had intended the hailing message as an experiment; there was no preparation for how to develop further communications. While the three in the pinnace debated what to do, the Ring sent a second bitmap to the pinnace: 1, 3, 5, 7, 11, 13, 1, 4, 2, 1, 5, 9.

Then a third bitmap: 1, 3, 5, 7, 11, 13, 16, 6, 10, 10, 4, 7.

A fourth: 1, 3, 5, 7, 11, 13, 19, 5, 1, 15, 4, 8.

A fifth: 1, 3, 5, 7, 11, 13, 7, 2, 16, 4, 1, 14.

The bitmaps came one after another. The first six numbers in each consisted of the six prime numbers sent by the pinnace as a greeting. As for the next six numbers in each series, both Lieutenant Zhuo and Dr. West turned to Guan Yifan, the scientist. The cosmologist stared at the scrolling numbers in the floating window and shrugged.

“I can’t see any pattern.”

“Then let’s suppose that there is no pattern.” West pointed at the window. “The first six numbers were sent by us, so it’s possible that they mean ‘you.’ The next six numbers in the transmissions show no recognizable pattern, so maybe they mean ‘all’—‘everything about you.’”

“They—or it—want to know everything about us?”

“Or at least a linguistic sample. It wants to decode it, study it, and then communicate with us further.”

“Then we should send it the Rosetta System.”

“We have to ask for authorization.”

The Rosetta System was a database developed to teach Earth languages to Trisolarans. The database included about two million characters’ worth of documents concerning the natural and human histories of Earth with numerous videos and images. There was also software to draw connections between the linguistic symbols and the images so that an alien civilization could decode and study Earth languages.

The mother ship authorized the request from the exploration team. But the pinnace didn’t have the Rosetta System in its onboard computer memory, and due to the extremely tenuous communication link between the pinnace and the mother ship, it was impossible to transmit such a large volume of data. The only solution was to have the mother ship beam the information directly at the Ring. This couldn’t be done via radio, but luckily, Gravity was equipped with a neutrino communication system. They weren’t sure if the Ring could receive neutrino signals, however.

Three minutes after Gravity transmitted the Rosetta System via a neutrino beam to the Ring, the pinnace received a new series of bitmaps from the Ring. The first one was a perfect square of sixty-four dots arranged eight by eight; the second bitmap was missing one dot in a corner, leaving sixty-three; the third bitmap was missing two, leaving sixty-two….

“It’s a countdown, or a progress bar,” said West. “I think this is to show that it has received the Rosetta System and is in the process of decoding it. We should wait.”

“Why sixty-four dots?”

“It’s a reasonably big number if you’re in base two. It’s like how we use one hundred for lots of things in base ten.”

Lieutenant Zhuo and Guan were both glad to have West with them. The psychologist did seem to have some skills when it came to establishing communications with unknown intelligences.

When the countdown reached fifty-seven, something exciting happened: The next number didn’t come in the form of a bitmap of dots. The Ring transmitted the Arabic number 56.

“Wow, fast learner,” Guan said.

The number kept on decreasing by one every ten seconds or so. A few minutes later, the number reached 0. The last message consisted of four Chinese characters:

I am a tomb.

The Rosetta System was written in a language that mixed English with Chinese. It would make sense that the Ring would use the same language to communicate with them. It just happened that this message consisted entirely of Chinese characters. Guan Yifan typed a question into the floating window, and began the conversation between humanity and the Ring.

Whose tomb is this?

The tomb of those who created it.

Is this a spaceship?

It used to be a spaceship. But now it’s dead, and so it’s a tomb.

Who are you? Who is conversing with us?

I am the tomb. It is the tomb speaking to you. I’m dead.

You mean you’re a ship whose crew died? In other words, you’re the control system for the ship?

(There was no reply to this.)

We can see many other objects in this region of space. Are they also tombs? 

Most of them are tombs. The others will be tombs soon. I don’t know them all. 

Are you from far away? Or have you always been here? 

I’m from far away; they’re also from far away, from different places far away. 

Where?

(There was no answer.)

Did you build this four-dimensional fragment?

You told me that you came from the sea. Did you build the sea?

Are you saying that for you, or at least for your creators, this four-dimensional space is like the sea for us?

More like a puddle. The sea has gone dry.

Why are so many ships, or tombs, gathered in such a small space?

When the sea is drying, the fish have to gather into a puddle. The puddle is also drying, and all the fish are going to disappear.

Are all the fish here?

The fish responsible for drying the sea are not here.

We’re sorry. What you said is really hard to understand.

The fish who dried the sea went onto land before they did this. They moved from one dark forest to another dark forest.

The last sentence was like a thunderclap. The three inside the pinnace cabin and everyone in the distant two mother ships hearing the exchange via a faint link all shuddered.

Dark forest… what do you mean?

The same thing you mean.

Are you going to attack us?

I’m a tomb; I’m dead; I won’t attack anyone. There is no dark forest state between spaces of different dimensions. The lower-dimensional space cannot threaten the higher-dimensional space, and the resources of the lower-dimensional space are of no use to the higher-dimensional space. But the dark forest exists everywhere between those sharing the same dimensions.

Can you give us any suggestions?

Leave this puddle immediately. You are thin pictures. You’re fragile. If you stay in the puddle, you’ll turn into tombs in no time…. Wait, there seem to be fish on your pinnace.

Guan sat there, stunned for a few seconds, and then realized that the pinnace really did have some fish. He always carried an ecological sphere with him, about the size of a fist. Inside the glass sphere was water, a tiny fish, and some seaweed; together, everything formed a carefully designed miniature enclosed ecosystem. This was Guan’s favorite possession, so he had taken it with him on this adventure. If he couldn’t return, this would have accompanied him into the afterlife.

I like fish. Can I have it?

How do we give it to you?

Toss it over.

The three put on the helmets for their space suits and opened the pinnace’s hatch. Guan lifted the ecological sphere to his eyes. Carefully, since he was in four-dimensional space, he held the sphere by its three-dimensional edge, and gave it a final glance. From this four-dimensional perspective, every detail in the sphere was revealed, and this tiny world of life seemed even more rich, varied, and colorful. Guan swung his arm and tossed the sphere in the direction of the Ring. He watched as the small, transparent sphere disappeared in space. Then he closed the hatch and continued the conversation.

Is this the only puddle in the universe?

There was no answer. After that, the Ring remained silent and responded no more to attempts at communication.

Gravity informed them that more micrometeoroids had struck Blue Space. An increasing number of drifting objects, including some small-scale four-dimensional objects, possibly debris from ships or other artifacts, surrounded both ships. Captain Chu ordered their immediate return. The plan to board the Ring had to be scrapped.

Since they now knew their distance from the mother ship, the return trip could be covered twice as fast. In two hours, they were back in the vicinity of Blue Space, and successfully located a warped point to return home.

The explorers were treated as heroes and given a celebratory welcome—even if their discoveries appeared to yield no practical applications for the future of the two ships.

Captain Chu asked, “Dr. Guan, what do you think is the answer to the last question you asked the Ring?”

“I go back to the analogy I made before. The probability that we managed to stumble into the only soap bubble with a diameter of forty to fifty astronomical units on the surface of a sheet of paper sixteen billion light-years across is so minuscule that it might as well be zero. I’m certain that there are other soap bubbles, probably many more.”

“Do you think we’ll encounter more in the future?”

“I think there’s an even more interesting question: Have we encountered them before? Think about the Earth: It’s been careening through space for several billion years. Is it not possible that it had entered a four-dimensional fragment in the past?”

“That would have been an astonishing sight. I find it hard to imagine that humanity had experienced it…. But I wonder if dinosaurs could have located warped points…”

“Why are there bubbles at all? Why are there so many four-dimensional fragments in three-dimensional space?”

“It’s a great mystery.”

“Captain, I think it’s likely a dark secret.”

Blue Space and Gravity began to back out of the fragment. As the ships accelerated, gravity pulled them toward the ships’ sterns. Guan Yifan and the science officers from both ships tried to cram as much research about the fragment as possible into the next few days and spent almost all their time in four-dimensional space. This was only in part due to the requirements of their research—they also found the confinement and claustrophobia of being in three-dimensional space unbearable.

On the fifth day after beginning acceleration, all those in four-dimensional space found themselves back in three-dimensional space in a flash without having passed through a warped point. The electromagnetic sensors on the two ships indicated that there were no more warped points aboard either ship.

Blue Space and Gravity were outside the fragment.

This surprised them. Based on their calculations, they should still be cruising through the fragment for another twenty hours. Their early exit was probably due to one of two reasons: one, the fragment had sped up in a direction opposite to the ships’ current heading. Two, the fragment was shrinking. The crews believed reason number two was more likely. Other than the data, they also remembered the answer from the Ring:

The two ships stopped accelerating and began to decelerate at full power. Finally, they stopped at the vicinity of the boundary of the four-dimensional fragment, where it was safe.

The edge of the four-dimensional fragment was invisible. The space before them was empty, placid like the surface of a deep pool. The sea of stars that was the Milky Way shone brightly, giving no hint that a great secret was hidden close by.

But soon they did notice a strange and spectacular sight: From time to time, luminous lines appeared in the space before them. Those lines were very thin, and very straight on first appearance. They seemed to have no thickness to the naked eye, and stretched in length between five thousand and thirty thousand kilometers. The lines appeared suddenly. At first, they gave off a blue glow. Then the color gradually shifted to red, and the straight lines curved and broke into many pieces, until they finally vanished. Observation showed that these lines manifested at the edge of the fragment, as though a giant pen constantly marked out the boundary.

They launched an unmanned probe toward the region of space where the lines appeared, and by luck, the probe managed to observe one of the lines when it flashed into existence at close range. The probe was about a hundred kilometers away, rushing toward the line at full speed. By the time it arrived, the line had curled, broken up, and disappeared. The probe detected massive quantities of hydrogen and helium in the vicinity, and also some dust from heavy elements, mainly iron and silicon.

After analyzing the data, Guan and the science officers concluded that the lines were created by four-dimensional matter entering three-dimensional space. As the fragment shrank, four-dimensional matter dropped into three-dimensional space and decayed instantly. Although these bits of matter took up very little volume in four-dimensional space, their decay into three dimensions flattened the fourth dimension, causing their volume to increase greatly and expand into the form of straight lines. By their calculations, a few tens of grams of four-dimensional matter could form a line stretching almost ten thousand kilometers in three dimensions.

Based on the rate at which the boundary of the fragment was receding, in twenty days or so, the Ring would also enter three-dimensional space. The two ships decided to wait to observe such a wonder of the universe—they had plenty of time, after all. Using the glowing decay-lines as markers, the two ships cautiously proceeded, maintaining the same speed as the receding edge of the fragment.

During the next dozen or so days, Guan Yifan was absorbed in deep thought and calculations, and the science officers engaged in vigorous debates. Finally, they reached the consensus that, based on current theoretical physics, they could not do too much theoretical analysis of the four-dimensional fragment. But the theories that had been developed in the past three centuries could at least make some predictions that were confirmed by observations: A higher dimension existing in macro form decayed toward lower dimensions as inevitably as water fell over a cliff. The decay of four-dimensional space into three dimensions was the root cause of the fragment’s shrinking.

But the lost dimension wasn’t truly lost: It simply curled up from the macroscopic to the microscopic and became one of the seven dimensions folded up within the quantum realm.

They could again see the Ring with the naked eye. The existence of this self-declared tomb would soon end in three-dimensional space.

Both Blue Space and Gravity stopped advancing and backed off three hundred thousand kilometers. As the Ring entered three-dimensional space, the decay process would release tremendous amounts of energy—this was why the lines that appeared earlier had given off so much light.

Twenty-two days later, the edge of the fragment receded past the Ring. The moment the Ring entered three-dimensional space, the universe seemed to be cut in half. The cut surface glowed with a blinding light, as though a star had been pulled into a line in an instant. From the spaceships it was impossible to see the end points, but it was as if God had held a T-square against the plan for the universe and sketched a line straight across from left to right. Careful observation by instruments revealed that the line was close to one AU in length, or about 130 million kilometers, almost long enough to connect the Earth with the Sun. In contrast to other lines that had been observed, this one had a thickness that was visible even from several hundred thousand kilometers away. The light emitted by the line turned from a hot bluish-white to a merely warm red, and then gradually dimmed. The line itself also became twisted and loose, breaking into a belt of dust. It no longer glowed by itself, but seemed suffused with the light of the stars, a serene silver. Observers from both ships shared a strange impression: The dust belt resembled the Milky Way in the background. What had happened seemed to be the flash of a giant camera that took a picture of the galaxy. Afterwards, the photograph slowly developed in space.

Guan felt a trace of sorrow in the face of such a majestic sight. He was thinking of the ecological sphere he had given to the Ring. It wasn’t able to enjoy the gift for long. As it decayed into three-dimensional space, the Ring’s internal four-dimensional structures were annihilated instantaneously. Those other dead or dying ships within the fragment would not be able to escape a similar fate in the end. In this vast universe, they could only persist for a time in the tiny four-dimensional corner.

A vast and dark secret.

Blue Space and Gravity sent out many probes to the dust belt. Other than scientific investigation, they also wanted to see if they could gather some useful resources. The Ring had decayed into common elements in three-dimensional space: mostly hydrogen and helium. These could be collected as fuel for nuclear fusion. However, since these elements existed mostly in the form of gas in the dust belt, they dissipated quickly, and in the end very little was collected. There were also some heavy elements, however, and they were able to gather some useful metals.

The two ships now had to consider their own future. A temporary council formed of the crews of both Blue Space and Gravity announced that everyone could pick between continuing the journey with the two ships or returning to the Solar System.

An independent hibernation ark would be constructed and powered by one of the seven fusion reactors on the two ships. Anyone wishing to go home would board this ark and return to the Solar System after a voyage of thirty-five years. The two ships would inform the Earth of the hibernation ark’s course via a neutrino transmission so that the Earth could dispatch ships to meet it upon arrival. In order to prevent Trisolaris from locating Blue Space and Gravity based on this transmission, the neutrino transmission would only be made after the hibernation ark had already been on its way for some time. If the Earth could send out ships to assist the ark with deceleration before its arrival, more of the ark’s fuel could be spent for acceleration and shorten the voyage to between ten and twenty years.

Assuming the Earth and the Solar System still existed by then.

Only about two hundred people chose to return. The rest didn’t want to go back to that world doomed to destruction; they would rather stay with Blue Space and Gravity and continue into the unknown depths of space.

A month later, the hibernation ark and the two ships both embarked on their new voyages. The hibernation ark headed for the Solar System, while Blue Space and Gravity planned to divert around the four-dimensional fragment and then aim for a new target star system.

The luminous glow from the fusion reactors lit up the already sparse dust belt and cast it in a golden-red hue, like a warm sunset on Earth. Everyone, whether homeward bound or heading far away, felt hot tears filling their eyes. The beautiful space sunset quickly faded, and the eternal night fell over everything.

The two seeds of human civilization continued to drift into the depths of the starry sea. Whatever fate held in store for them, at least they were starting again.