Death's End

Bunker Era, Year 11 Bunker World

#37813, your hibernation is at an end. You have been in hibernation for 62 years, 8 months, 21 days, and 13 hours. Your remaining hibernation allotment is 238 years, 3 months, 9 days. This is Asia Hibernation Center #1, Bunker Era, Year 11, May 9, 2:17 P.M.

The small information window hovered in front of the just-awakened Cheng Xin for no more than a minute before disappearing. She looked at the smooth metallic ceiling. Out of habit, she stared at a certain spot in the ceiling. During the age she last entered hibernation, doing so would have caused the ceiling to recognize her gaze and bring up an information window. But the ceiling didn’t respond. Although she still didn’t have the strength to turn her head, she was able to see part of the room: All the walls were made of metal and there were no information windows. The air remained empty as well, with no holographic displays. The metal in the wall looked familiar: stainless steel or aluminum alloy, no decorations.

A nurse appeared in her field of view. She was very young and didn’t look at Cheng Xin. Instead, the nurse busied herself around her bed, probably disconnecting the medical equipment attached to her body. Cheng Xin’s body couldn’t sense what the nurse was doing, but something about the nurse seemed familiar to her—her uniform. During the last age Cheng Xin was awake, people wore self-cleaning clothes that always looked brand new, but this nurse’s white uniform showed signs of wear. Although it was still clean, she could see signs of it being old, signs of the passage of time.

The ceiling began to move. Cheng Xin’s bed was being pushed out of the awakening room. She was astonished to find that the nurse was pushing the bed—the bed actually needed someone to push it to move.

The hallway was made of empty metallic walls as well. Other than some ceiling lights, there were no other decorations. The lights looked ordinary enough, and Cheng Xin saw that the frame around one of the lights was loose and dangled from the ceiling. Between the frame and the ceiling she saw… wires.

Cheng Xin struggled to recall the information window she had seen upon first awakening, but she couldn’t be certain it had really been there. It now seemed a hallucination.

There were many pedestrians in the hallway, and no one paid attention to Cheng Xin. She concentrated on the clothes people wore. A few were medical personnel in white uniforms, and the rest wore simple, plain clothing that resembled work overalls. Cheng Xin had the impression that many people here seemed to be from the Common Era, but soon realized that she was wrong. The Common Era was a long time ago, and the human race had changed eras four times already. It was impossible for so many Common Era people to be around.

Her impression was due to the fact that she saw some men who looked like the men she was used to.

The men who had disappeared during the Deterrence Era had returned. This was another age capable of producing men.

Everyone seemed to be in a hurry. This seemed to be another swing of the pendulum: the leisure and comfort of the last age had disappeared, and it was once again a harried society. In this age, most people no longer belonged to the leisure class, but had to work for a living.

Cheng Xin’s bed was pushed into a small room. “Number 37813 awakened without irregularities,” the nurse called out. “She’s in recovery room twenty-eight.” Then the nurse left and closed the door. Cheng Xin noticed that she had to pull the door shut.

She was left alone in the room. For a long time, no one came to check on her, a situation in total contrast to the previous two awakenings she had experienced, when she had received a great deal of attention and care. She was certain of two things: First, in this age, hibernation and awakening were common events. Second, not many people knew that she had awakened.

After Cheng Xin recovered some motor control, she moved her head and saw the window. She remembered the world before she had gone into hibernation: The hibernation center had been a giant tree at the edge of the city, and she had been in one of the leaves near the top, from where she could see the grand city-forest. But now, outside this window, she could only see a few ordinary buildings erected on the ground, all of them the same shape and design. Based on the sunlight glinting off them, they were constructed of metal as well. The buildings gave her the feeling of having returned to the Common Era.

She suddenly wondered if she had just awakened from a long dream. The Deterrence Era, the Broadcast Era—they were all dreams. Although the memories were clear, they seemed too surreal, fantastic. Perhaps she had never leapt across time on three occasions, but had been in the Common Era all along?

A holographic display window appeared next to her bed, removing her doubts. The window contained only a few simple buttons that could be used to call for the doctor and the nurse. The place seemed very familiar with the hibernation recovery process: The window had appeared just as Cheng Xin recovered the ability to lift her hand. But it was only a small window; the hyperinformation society where information windows filled every surface was gone.

Unlike the previous two awakenings, Cheng Xin recovered very quickly. By the time it was dark out, she was already able to get out of bed and walk about a bit. She found that the center provided only the simplest services. A doctor came in once to give her a cursory examination and then left; she had to do everything else by herself. She had to bathe herself while she still felt weak all over. As for meals, if she hadn’t asked for them through that tiny holographic display, she might never have gotten to eat. Cheng Xin wasn’t annoyed by this lack of solicitousness, as she had never completely adjusted to that excessively generous era where every person’s every need was taken care of. She was still a Common Era woman at heart, and she felt at home here.

The next morning, a visitor came to see her. She recognized Cao Bin right away. This physicist had once been the youngest Swordholder candidate, but now he was much older, and a few strands of white appeared in his hair. Cheng Xin was certain, though, that he had not aged by sixty-two years.

“Mr. Thomas Wade asked me to come and get you.”

“What happened?” Cheng Xin’s heart sank as she recalled the conditions for her awakening.

“We’ll talk about it after we get there.” Cao Bin paused, and then added, “I’ll take you around this new world before then so that you can make the right decision based on facts.”

Cheng Xin glanced at the undistinguished buildings outside the window; she didn’t feel the world was new.

“What happened to you? You weren’t awake these last sixty years,” Cheng Xin asked.

“I went into hibernation at about the same time you did. Seventeen years later, the circumsolar particle accelerator was operational, and I was awakened to research basic theory. That took fifteen years. Later, the research work turned to technical applications, and I was no longer needed, so I went back into hibernation until two years ago.”

“How’s the curvature propulsion project going?”

“There have been some developments…. We’ll talk about it later.” Cao Bin clearly didn’t relish the topic.

Cheng Xin looked outside again. A breeze passed by, and a small tree in front of the window rustled. A cloud seemed to pass overhead, and the glint given off by the metallic buildings dimmed. How could such a commonplace world have anything to do with lightspeed spaceships?

Cao Bin followed Cheng Xin’s gaze and laughed. “You must feel the same as when I first awakened—rather disappointed in this era, aren’t you?… If you are up to it, let’s go outside and take a look.”

Half an hour later, Cheng Xin, dressed in a white outfit appropriate for this era, came onto a balcony of the hibernation center with Cao Bin. The city spread out before her, and Cheng Xin was again struck by the feeling that time had flowed backwards. After she had awakened for the first time during the Deterrence Era, the impact of seeing the giant forest-city for the first time was indescribable. After that, she never thought she would again see a cityscape so familiar: The plan for the city was very regular, as though all the buildings had been erected at once. The buildings themselves were monotonous and uniform, as though designed solely for utility with no consideration for architectural aesthetics. All of them were rectangular with no surface decorations, and all sported the same metallic gray exterior—reminding her strangely of the aluminum lunch boxes of her youth. The buildings were neatly and densely arranged as far as she could see. At the horizon, the ground rose up like the side of a mountain, and the city extended onto the mountainside.

“Where is this?” Cheng Xin asked.

“Hmm, why is it overcast again? We can’t see the other side.” Cao Bin didn’t answer her question, but shook his head at the sky in disappointment, as though the weather had something to do with Cheng Xin’s understanding of this new world. But soon, she saw how strange the sky was.

The sun was below the clouds.

The clouds began to dissipate, revealing a large opening. Through the opening, Cheng Xin did not see a blue sky; instead, she saw… more ground.

The ground in the sky was studded with the buildings of a city very similar to the city around her, except she was now looking “down”—or “up”—at it. This must have been the “other side” Cao Bin referred to. Cheng Xin realized that the rising “mountainside” in the distance wasn’t a mountain at all, but continued to rise until it connected with the “sky.” The world was a giant cylinder, and she was standing on the inside of it.

“This is Space City Asia I, in the shadow of Jupiter,” Cao Bin said.

The new world that had seemed so common a moment ago now stunned her. Cheng Xin felt that she had finally, truly awakened.

In the afternoon, Cao Bin brought Cheng Xin on a trip to the gateway terminal at the northern end of the city.

By custom, the central axis of the space city was treated as oriented north-south. They got on a bus outside the hibernation center—this was a real bus that moved along the ground; probably running on electricity, but it looked indistinguishable from an ancient city bus. The bus was crowded, and Cheng Xin and Cao Bin took the last two seats at the back so that additional passengers had to stand. Cheng Xin thought back to the last time she had taken a bus—even during the Common Era, she had long ceased riding crowded public transportation.

The bus moved slowly, so she could take in the view leisurely. Everything now held a new meaning for her. She saw swaths of buildings sweep past the window, interspersed with green parks and pools; she saw two schools with exercise yards painted in blue; she saw brown soil covering the ground on the sides of the road, looking no different from soil on Earth. Broad-leafed trees resembling Chinese parasol trees lined the road, and advertising billboards appeared from time to time—Cheng Xin didn’t recognize most of the products or brands, but the style of the ads was familiar.

The main difference from a Common Era city was that the entire world seemed to be constructed out of metal. The buildings were metallic, and the inside of the bus seemed to be mostly metal as well. She saw no plastic, and no composites either.

Cheng Xin paid the most attention to the other passengers on the bus. Across the aisle sat two men, one of whom dozed with a black briefcase on his lap, while the other wore yellow work overalls with black oil stains. Next to the man’s feet was a tool bag, and some instrument Cheng Xin did not recognize poked out of it: It resembled an ancient power drill, but was translucent. The man’s face showed the exhaustion and numbness of someone who performed physical labor. The last time Cheng Xin had seen such an expression was on the faces of migrant laborers in Common Era cities. In front of her sat a young couple. The man whispered something in the woman’s ear, and the woman giggled from time to time while spooning something pink out of a paper cup—ice cream, since Cheng Xin picked up the sweet fragrance of cream, no different from her memory of more than three centuries ago. Two middle-aged women stood in the aisle—they were of a type familiar to Cheng Xin: The drudgery of everyday life had ground away their glamour, and they no longer took care with their appearance or were fashionable. Women like that had disappeared during the Deterrence Era or the Broadcast Era. Back then, women always had smooth, delicate skin, and no matter how old they were, they looked beautiful and refined, appropriate for their age. Cheng Xin eavesdropped on their conversation:

“You got it wrong. The morning market and the evening market have similar prices. Don’t be lazy. Go to the wholesale market on the west side.”

“They don’t have enough, and they won’t sell at wholesale prices anyway.”

“You have to go later, after seven or so. The vegetable vendors will be gone, and they’ll sell at wholesale prices.”

She overheard snippets of other conversations in the bus as well.

“The city government is different from the atmospheric system, much more complicated. When you get there, pay attention to the office politics. Don’t get too close to anyone at first, but don’t hold yourself apart either.”…“It’s not right to charge separately for the heat; that should have been included in the electric bill.”…“If they had subbed for that fool earlier they wouldn’t have lost so badly.”…“Don’t be so disappointed. I’ve been here since the city was built, and how much do you think I make every year?”…“That fish is no longer fresh. Don’t even think about steaming it.”…“The other day, when they had to make an orbital adjustment, Park Four’s water spilled again and flooded a large area.”…“If she doesn’t like him, he should just give up. All that effort is just going to be wasted.”…“That can’t be authentic. I don’t even think it’s a high-quality imitation. Are you kidding me? At that price?”…

Cheng Xin’s heart felt warm and content. Ever since she had awakened for the first time during the Deterrence Era, she had been searching for this feeling. She had thought she’d never find it. She absorbed the conversations around her as though slaking a thirst, and didn’t pay much attention to Cao Bin’s narration of the city.

Space City Asia I was one of the earliest to be built as part of the Bunker Project. It was a regular cylinder that simulated gravity with the centrifugal force generated by spinning. With a length of thirty kilometers and a diameter of seven kilometers, its usable interior surface area was 659 square kilometers, about half the size of ancient Beijing. Once, about twenty million inhabitants had lived here, but after the completion of newer cities, the population had decreased to about nine million, so that it was no longer so crowded….

Cheng Xin saw another sun appear in the sky before her. Cao Bin explained that there were a total of three artificial suns in the space city, all of them floating along the central axis, each separated by about ten kilometers. These produced energy by nuclear fusion, and brightened and dimmed on a twenty-four-hour cycle.

Cheng Xin felt a series of jolts. The bus was already at a stop, and the tremors seemed to originate from deep within the ground. She felt a force pushing against her back, but the bus remained unmoving. Outside the window, she could see the shadows cast by the trees and buildings suddenly shift to a new angle as the artificial suns abruptly shifted positions. But soon, the suns moved back into place. Cheng Xin saw that none of the passengers seemed surprised by this.

“The space city was adjusting its position,” said Cao Bin.

The bus arrived at the last stop after about thirty minutes. After getting off the bus, she saw that the everyday scenes that had so intoxicated her disappeared. In front of her was an enormous wall whose immense size made her gasp. It was as though she was standing at the end of the world—and indeed, she was. This was the “northernmost” point in the city, a large circular disk eight kilometers in diameter. She couldn’t see the entire disk from where she stood, but she could tell that the ground rose up on both sides of her. The top of the disk—the other side of the city—was about as high as the peak of Mount Everest. Many radial spokes converged from the rim of the disk to the center, four kilometers above. Each spoke was an elevator shaft, and the center was the space city’s gateway.

Before entering the elevator, Cheng Xin cast a lingering glance back at this city that already seemed so familiar. From here, all three suns were visible in a row toward the other end of the city. It was dusk, and the suns dimmed, turning from a blinding orange-white to a gentle red, bathing the city in a warm golden glow. Cheng Xin saw a few girls in white school uniforms chatting and laughing on a lawn not too far away, their hair wafting in the breeze and drenched in the golden glow of the evening sun.

The interior of the elevator car was very spacious, like a large hall. The side facing the city was transparent, turning the car into an observation deck. Every seat was equipped with seat belts because, as the elevator rose, gravity quickly diminished. As they looked outside, the ground sank lower, while the “sky,” another ground, grew clearer. By the time the elevator reached the center of the circle, gravity had completely disappeared, as well as the sensation of “up” and “down” when looking outside. Since this was the axis around which the city spun, the ground surrounded them in every direction. Here, the view of the city was at its most magnificent.

The three suns had dimmed to the level of moonlight, and their colors shifted to silver. Viewed from here, the three suns—or moons—were stacked on top of each other. All the clouds were concentrated in the gravity-free zone, forming an axis of white mist extending through the center of the city to the other end. The “southern” end, forty-five kilometers away, could be seen clearly. Cao Bin told Cheng Xin that that was where the city’s thrusters were located. The lights of the city had just come on. In Cheng Xin’s eyes, a sea of lights surrounded her and extended into the distance. She seemed to be looking down a giant well whose wall was covered with a brilliant carpet.

Cheng Xin casually locked her gaze on a certain spot in the city, and found the arrangement of buildings there very similar to the residential district of her home back in the Common Era. She imagined a certain ordinary apartment building in that area and a certain window on the second floor: Through blue curtains, a gentle light seeped, and behind the curtain, her mom and dad waited for her….

She could not hold back her tears.

Ever since awakening for the first time during the Deterrence Era, Cheng Xin had never been able to integrate into the new eras, always feeling like a stranger from another time. But she could never have imagined that she would once again feel at home more than half a century later, here behind Jupiter, more than eight hundred million kilometers from the Earth. It was as if everything that she had been familiar with from more than three centuries ago had been picked up by a pair of invisible hands, rolled up like a giant painting, and then placed here as a new world slowly spinning around her.

Cheng Xin and Cao Bin entered a weightless corridor. This was a tube in which people moved by pulling themselves along handholds on cables. The passengers riding up from all the elevators along the rim gathered here to exit the city, and the corridor was filled with streaming crowds. A row of information windows appeared around the circular wall of the corridor, and the animated images in the windows were mostly news and ads. But the windows were few in number and neatly arranged, unlike the chaotic profusion of information windows in the previous era.

Cheng Xin had long since noticed that the overwhelming hyperinformation age had apparently ended. Information appeared in this world in a restrained, directed manner. Was this the result of changes in the Bunker World’s political and economic systems?

Emerging from the corridor, Cheng Xin first noticed the stars spinning overhead. The spin was very rapid and made her dizzy. The view around her opened up dramatically. They were standing on a circular plaza with a diameter of eight kilometers “atop” the space city. This was the city’s spaceport, and many spacecraft were parked here. Most of the vessels were shaped not too differently from those Cheng Xin had seen over sixty years ago, though these were generally smaller. Many were about the size of ancient automobiles. Cheng Xin noticed that the flames at the nozzles of the spaceships as they took off were far dimmer than what she remembered from more than half a century ago. The glow was a dark blue and no longer so blinding. This probably meant that the miniature fusion engines were much more efficient.

Cheng Xin saw an eye-catching red-glowing circle all around the exit, with a radius of about a hundred meters. She quickly understood its meaning: The space city was spinning, and, outside the circle, the centrifugal force became very strong. Moving outside the warning circle meant a dramatic increase in centrifugal force, and vessels parked out there had to be anchored, while pedestrians needed to wear magnetic shoes lest they be thrown out.

It was very cold here. Only when a nearby vessel took off did the engine’s heat bring a brief feeling of warmth. Cheng Xin shuddered—not just from the cold, but because she realized that she was completely exposed to space! But the air around her and the air pressure were real, and she could feel cold breezes. It appeared that the technology to contain an atmosphere in a nonenclosed area had advanced even further, to the point where an atmosphere could be maintained in completely open space.

Cao Bin saw her shock and said, “Oh, right now we can only maintain an atmosphere about ten meters thick above ‘ground.’” He hadn’t been in this world for too long, either, but he was already jaded by the technology that seemed like magic to Cheng Xin. He wanted to show her far more impressive sights.

Against the background of the spinning stars, Cheng Xin saw the Bunker World.

From here, most of the space cities behind Jupiter could be seen. She saw twenty-two cities (including the one she stood on), and there were four more blocked by the city they stood on. All twenty-six cities (six more than planned) were hiding in the shadow of Jupiter. They were loosely lined up in four rows, and reminded Cheng Xin of the spaceships lined up behind the giant rock in space more than sixty years ago. To one side of Asia I was North America I and Oceania I, and to the other side was Asia III. Only about fifty kilometers separated Asia I from its neighbors on either side, and Cheng Xin could feel their immensity, like two planets. The next row of four cities was 150 kilometers away, and it was difficult to tell their size visually. The most distant space cities were about one thousand kilometers away, and looked like delicate toys from here.

Cheng Xin thought of the space cities as a school of tiny fish hovering in place behind a giant rock to avoid the torrents in the river.

North America I, closest to Asia I, was a pure sphere. It and the cylindrical Asia I represented the two extremes of space city design. Most of the other space cities were football-shaped, though the ratios of major to minor axes were different in each. A few other space cities took on unusual shapes: a wheel with spokes, a spindle, etc.

Behind the other three gas giants were three more space city clusters, consisting of a total of thirty-eight space cities. Twenty-six were behind Saturn, four behind Uranus, and eight more behind Neptune. Those space cities were in safer locations, though the environs were even more desolate.

One of the space cities in front suddenly emitted a blue light. It was as though a small blue sun appeared in space, casting long shadows of the people and spaceships on the plaza. Cao Bin told Cheng Xin that this was because the space city’s thrusters had been activated to adjust its position. The space cities revolved around the Sun in parallel with Jupiter, just outside its orbit. Jupiter’s gravity gradually pulled the cities closer, and the cities had to constantly adjust their positions with thrusters. This operation required a great deal of energy. Once, the suggestion had been floated to turn the cities into Jupiter’s satellites that would only shift into new orbits around the Sun after the issuance of a dark forest strike warning. But until the advance warning system had been further refined and proven to be reliable, no space city wanted to take the risk.

“Lucky you! Now you get to see a sight that happens only once every three days.” Cao Bin pointed into space. Cheng Xin saw a tiny white dot in the distance, gradually growing bigger. Soon, it was a white sphere as big as a Ping-Pong ball.

“Europa?”

“That’s right. We’re very close to its orbit right now. Watch your footing and don’t be scared.”

Cheng Xin tried to figure out what Cao meant. She had always thought of celestial bodies as moving slowly, almost imperceptibly—as they did in most Earth-based observations. But then she remembered that the space city was not a Jovian satellite but remained stationary relative to it. Europa, on the other hand, was a satellite that moved very fast. She remembered its speed was about fourteen kilometers per second. If the space city was very close to Europa’s orbit, then…

The white sphere expanded rapidly—so fast that it seemed unreal. Europa soon took up most of the sky, and turned from a Ping-Pong ball into a giant planet. The sensation of “up” and “down” switched in an instant, and Cheng Xin felt as if Asia I were falling toward that white world. Next, the three-thousand-kilometer-diameter moon swept overhead so that for an instant, it took up the entire sky. The space city was skimming over the icy oceans of Europa, and Cheng Xin could clearly see the crisscrossing lines in that frozen landscape, like lines in a giant palm print. The air, disturbed by the passage of Europa, whipped around her, and Cheng Xin felt an invisible force dragging her from left to right—if she weren’t wearing magnetic shoes, she was sure she’d be pulled off the ground. Whatever was nearby that hadn’t been secured to the ground flew up, and a few cables attached to spaceships also drifted into the air. A terrifying rumbling came from below her—it was the immense frame of the space city reacting to the rapidly shifting gravity field of Europa. It took only about three minutes for Europa to hurtle past Asia I, and then it was on the other side of the city and began to shrink rapidly. The eight space cities in the two front-most rows all activated their thrusters to adjust their positions after the disturbance caused by Europa. Eight fireballs lit up the sky.

“How… how close was that?” Cheng Xin asked in an unsteady voice.

“The closest approach, like you experienced just now, was a hundred and fifty kilometers, basically brushing right by us. We don’t really have a choice. Jupiter has thirteen moons, and it’s impossible for the space cities to avoid them all. Europa’s orbit is inclined only slightly from the equator, and so it’s very close to these cities here. It’s the main source of water for the Jovian cities, and we’ve built a lot of industry on it. But when the dark forest strike comes, all of it will have to be sacrificed. After the solar explosion, all of the Jovian moons’ orbits will shift dramatically. Maneuvering the space cities to avoid them at that time will be a very complicated operation.”

Cao Bin found the dinghy he had taken to come here. It was tiny, shaped and sized like an ancient automobile, capable of seating only two. Cheng Xin instinctively felt unsafe going into space in such a tiny vehicle, even though she knew her fear wasn’t reasonable. Cao Bin told the AI to go to North America I, and the dinghy took off.

Cheng Xin saw the ground receding quickly, and the dinghy flew along at a tangent to the spinning city. Soon, the eight-kilometer-diameter plaza came into view, followed by the entirety of Asia I. Behind the cylinder was a vast expanse of dark yellow. Only when the edge of this yellow expanse appeared did Cheng Xin realize that she was looking at Jupiter. Here, in the shadow of the gas giant, everything was cold and dark, and the Sun seemed to not exist at all. Only the phosphorescence of the planet’s liquid helium and hydrogen, diffused through the thick atmosphere, formed patches of hazy light roving about like eyeballs behind the closed eyelids of a dreamer. The immensity of Jupiter astonished Cheng Xin. From here, she could only see a small portion of its rim, and the rim’s curvature was minuscule. The planet was a dark barrier that blocked out everything, and once again gave Cheng Xin the feeling of standing at a giant wall at the end of the world.

In the following three days, Cao Bin took Cheng Xin to visit four more space cities.

The first was North America I, the closest city to Asia I. The main advantage of its spherical construction was that a single artificial sun at the center was sufficient to illuminate the entire city, but the disadvantage of such a design was obvious as well: The gravity changed depending on one’s latitude. The equator had the most gravity, which decreased as you went up in latitude. The polar regions were weightless. Inhabitants in the different regions had to adjust to life under various gravity conditions.

Unlike Asia I, small spacecraft could enter the city directly from the gateway at the north pole. Once the dinghy was inside, the entire world spun around it, and the dinghy had to match the city’s spin before landing. Cheng Xin and Cao Bin rode a high-speed rail to go to low-latitude regions, and the train moved far faster than the bus in Asia I. Cheng Xin saw that the buildings here were denser and taller, looking like a metropolis. At the high-latitude, low-gravity regions especially, the buildings’ heights were limited only by the volume of the sphere. Near the polar regions, some buildings were as tall as ten kilometers, looking like long thorns extending up from the ground toward the sun.

North America I had been completed early on. With a radius of twenty kilometers and twenty million inhabitants, it was the largest city by population. It acted as the prosperous commercial center for all the Jovian cities.

Here, Cheng Xin got to see a splendid sight that was absent from Asia I: the equatorial ring-ocean. As a matter of fact, most space cities had ring-oceans of various widths, and Asia I was rather unique in lacking one. In spherical or football-shaped cities, the equator was the lowest point in the city’s simulated gravity, and all the city’s water naturally collected there, forming a sparkling, undulating belt for the city. Standing on the shore, one could see the ocean rising on both sides and dividing the “sky” behind the sun. Cheng Xin and Cao Bin took a fast boat and navigated around the sea—a journey of some sixty kilometers. The water in the sea came from Europa, clear, cold, and reflecting rippling light onto the skyscrapers on both sides. The dikes along the edge of the sea closest to Jupiter were higher, to avoid the water spilling out when the city accelerated during position adjustments. Even so, when the city had to engage in unexpected maneuvers, small-scale flooding would occur from time to time.

Next, Cao Bin took Cheng Xin to Europe IV, which sported a typical football-shaped design. Its distinguishing characteristic was the lack of a common artificial sun. Every district had its own miniature fusion sun, and the tiny suns hovered about two hundred to three hundred meters high to provide illumination. The advantage of this approach was that the weightless axis could be more efficiently utilized. The axis of Europe IV was taken up by the longest—or tallest—building among all the space cities. It was forty kilometers long and connected the north and south poles of the football. Since the interior of the building was weightless, it was mainly used as a spaceport and commercial entertainment district.

Europe IV had the smallest population of all the cities, only 4.5 million. It was the wealthiest city of the Bunker World. The exquisite houses illuminated by miniature suns amazed Cheng Xin. Each house came with its own swimming pool, and a few had wide lawns. Tiny white sails dotted the serene equatorial sea, and people sat on the shore, fishing leisurely. She saw a yacht sail by slowly, and it looked as luxurious as any yacht on ancient Earth. There was a cocktail party being held aboard the yacht with live musicians…. She was astonished that such life could be transplanted into the shadow of Jupiter, eight hundred million kilometers from the Earth.

Pacific I, on the other hand, was the antithesis of Europe IV. This was the very first city completed by the Bunker Project, and like North America I, it was a sphere. Unlike all the other Jovian cities, it did orbit Jupiter as a satellite.

Millions of construction workers had lived in Pacific I during the early years of the Bunker Project. As the project progressed, it was used to warehouse construction materials. Later, as the numerous flaws of this early-phase experimental space city became apparent, it was abandoned. But, after the resettlement to the Bunker World had been completed, people began to live here again, and finally formed a city of their own, with a city government and police force. However, the authorities only maintained the most basic public infrastructure, and society was left basically to run on its own. Pacific I was the only city to which people were free to immigrate without a residential permit. Most of the population consisted of unemployed and homeless wanderers, poor people who had lost social security for various reasons, and bohemian artists. Later, it became the base for extremist political organizations.

Pacific I had no city thrusters, and there was no artificial sun inside. It also didn’t spin, so the interior was completely weightless.

After entering the city, Cheng Xin saw a fairy-tale world. It was as if a broken-down but once prosperous city had lost gravity abruptly, so that everything floated in the air. Pacific I was a city in permanent night, and each building maintained illumination with a nuclear battery. Thus, the interior was filled with glowing, floating lights. Most of the buildings in the city were simple shacks built from abandoned construction materials. Since there was no “up” or “down,” most of the shacks were cube-shaped, with windows (which also acted as doors) on all six sides. Some were shaped as spheres, which had the advantage of being more resilient, as the drifting buildings inevitably collided against each other.

There was no notion of land ownership in Pacific I because all the buildings drifted around with no permanent location. In principle, each resident had the right to use any space in the city. The city had a large number of homeless individuals who didn’t even possess a shack. All of their possessions were kept in a large net sling to prevent them from scattering everywhere, and the owners drifted along with the net slings. Transportation within the city was simple: There were no cars or weightless cables or personal thrusters. The residents moved around by pushing and kicking off buildings and drifting. Since the buildings were densely packed inside the city, one could navigate anywhere that way, but this method of locomotion required great skill. As Cheng Xin observed the residents flitting around the dense clusters of floating buildings, she was reminded of gibbons swinging easily from branch to branch.

Cheng Xin and Cao Bin drifted close to a group of homeless men gathered around an open fire. Such a fire would have been prohibited in any other city. The fuel seemed to be some kind of flammable construction material. Due to the weightlessness, the flames did not rise up, but formed a ball of fire floating in place. The way they drank was also special. They tossed alcohol out of bottles, forming liquid spheres in the air. Then the men, dressed in rags and with unshaven faces, drifted along with them, capturing the spheres with their mouths and swallowing. One of the drunken men vomited, and the vomit rushing out of his mouth propelled him back, sending him tumbling in midair….

Cheng Xin and Cao Bin came to a market. All the goods floated in the air, forming a heterogeneous mess illuminated by a few drifting lights, with customers and vendors drifting among the hovering objects. In this chaos, it seemed hard to tell what belonged to whom, but if a customer examined something closely, a vendor would drift over to haggle. The goods offered for sale included clothing, electronics, food and liquor, nuclear batteries of various capacities, small arms, and so on. There were also exotic antiques on sale. In one place, a few metallic fragments were offered at very high prices. The vendor claimed that it was debris gathered from the outer Solar System from warships destroyed during the Doomsday Battle—it was impossible to tell if he was telling the truth.

Cheng Xin was surprised to find a vendor who sold antique books. She flipped through a few—these books were not ancient for her. All the books drifted in a cloud, and many had their pages spread open like a flock of white-winged birds in the light…. Cheng Xin saw a small wooden box drift in front of her, marked as cigars. She caught it, and immediately a young boy kicked his way over and swore up and down that these were authentic ancient Havana cigars that had been preserved for close to two hundred years. Since they had dried out a bit, he was willing to let them go at a low price that she would not be able to find anywhere else in the Solar System. He even opened the box to let Cheng Xin see what she was getting. She agreed and bought them.

Cao Bin took Cheng Xin to the edge of the city—the inside face of the spherical hull. There were no buildings attached to the hull, and there was no soil—everything was left as bare as the day the city was constructed. It was impossible to tell the curvature in a small area, and they seemed to be standing on a large, flat plaza. Above them, the dense buildings of the city floated, and flickering lights projected onto the “plaza.” Cheng Xin saw that the hull was marked with all kinds of graffiti, stretching as far as she could see. These pictures were vibrant, wild, unrestrained, wanton and full of energy. In the shifting, uncertain light, they seemed to come alive, as though they were dreams deposited from the city above.

Cao Bin didn’t bring Cheng Xin deeper into the city. According to him, the center of the city was chaotic and rather violent. Gangs fought each other, and a few years ago, one of the gang fights had managed to rupture the hull, causing a massive decompression incident. Later, the gangs seemed to come to some kind of unspoken agreement, and settled their disputes in the center of the city, away from the hull.

Cao Bin also told Cheng Xin that the Federation Government had devoted enormous resources to build a social welfare system here in Pacific I. The six million or so inhabitants here were mostly unemployed, but at least they could get the basic necessities for life.

“What will happen here in the event of a dark forest strike?”

“Only annihilation. This city has no thrusters, and even if it did have them, it would be impossible to move it into the shadow of Jupiter and keep it there. Look—” He pointed to the drifting buildings. “If the city accelerated, everything would smash through the hull. Then the city would be like a bag with a hole in the bottom. If we receive a dark forest strike alert, the only thing that can be done is to evacuate the population to the other cities.”

As they left the floating city in eternal night, Cheng Xin gazed at it through the porthole of the dinghy. This was a city of poverty and homelessness, but it also possessed its own rich life, like a weightless version of the famous Song Dynasty painting, Along the River During the Qingming Festival.

She understood that compared to the last era, the Bunker World was not at all an ideal society. The migration to the rim of the Solar System had caused some toxic social conditions, long eliminated by progress, to reemerge. This wasn’t exactly regression, but a kind of spiraling ascent, a necessary condition for the exploration and settlement of new frontiers.

After they left Pacific I, Cao Bin brought Cheng Xin to see a few more space cities with unusual designs. One of them, fairly close to Pacific I, was a wheel with spokes, not unlike a larger version of the space elevator terminal station that Cheng Xin had visited more than sixty years ago.

Cheng Xin was a bit puzzled by the designs of the cities. As a matter of engineering, the wheel seemed ideal. It was far easier to construct than the large, hollow shells used by the other cities, and when completed, a wheel was stronger and better able to survive disasters, as well as being easier to expand.

Cao Bin’s succinct reply to Cheng Xin’s query was “world-sense.”

“What?”

“The sensation of being inside a world. A space city has to have ample interior volume and wide-open views so that the residents can feel they are living inside a world. Although the usable interior surface area isn’t too different from a hollow-shell design, in a wheel design, people always know that they are living inside a narrow tube or a series of such tubes.”

There were some other cities with even stranger designs. Most of these were industrial or agricultural centers with no permanent residents. For instance, there was a city called Resource I. Its length was 120 kilometers, but the diameter was only three kilometers, like a thin stick. It did not spin around the long axis, but rather, tumbled about its center, end over end. The city’s interior was divided into levels, and the gravity at each level differed dramatically. Only a few levels were suitable for living, while the rest were devoted to various industries adapted to the different gravities. According to Cao Bin, near Saturn and Uranus, there were cities formed by combining two or more stick-shaped cities into crosses or stars.

The earliest city clusters of the Bunker Project were built near Jupiter and Saturn. Later, as cities were built near Uranus and Neptune, some new city-design concepts emerged. The most important idea was city docking. In those two clusters at the edge of the Solar System, every city was equipped with one or more standardized docks so that cities could be interconnected. Docking multiplied the space available for inhabitants and created even better world-sense, greatly encouraging economic development. In addition, after docking, the atmospheres and ecological systems of the various cities merged, and that helped to stabilize their operation and maintenance.

Currently, most cities docked along their axis of spin. This way, after docking, the cities could continue to spin as before without changing the distribution of gravity. There were proposals for parallel or perpendicular docking as well, which would allow the combined cities to expand in multiple directions, as opposed to only along the axis of spin. But the spin of such combinations would dramatically change the interior distribution of gravity, and these proposals had not been tested so far.

The biggest combined city so far was located at Neptune, where four of the eight cities were docked together along their axis of spin, forming a two-hundred-kilometer-long combined city. When necessary—such as when a dark forest strike alert was issued—the combined city could be quickly taken apart to increase the mobility of each city. People hoped that, one day, all the cities in each cluster could be combined into one, so that humanity would live in four complete worlds.

In total, behind Jupiter, Saturn, Uranus, and Neptune, there were sixty-four large space cities and nearly a hundred medium and small cities, plus numerous space stations. Nine hundred million people lived in the Bunker World.

This was almost the entirety of the human race. Even before the arrival of the dark forest strike, Earth civilization had battened down the hatches.

Every space city was politically equivalent to a state. The four city clusters together formed the Solar System Federation, and the original UN had evolved into the Federation Government. Most of the Earth’s major ancient civilizations had passed through a city-state stage—and now, city-states had reemerged at the rim of the Solar System.

The Earth was now barely inhabited. Only about five million people remained there. These were individuals who did not wish to leave their home and who had no fear of the prospect of Death at any moment. Many brave men and women living in the Bunker World also traveled to Earth as tourists, though each journey meant gambling with their lives. As time passed, the anticipated dark forest strike loomed larger, and people gradually adapted to life in the Bunker World. Their yearning for their homeland lessened as they busied themselves in their new homes, and fewer and fewer now visited the Earth. The public no longer cared much about news from the home world, and were only vaguely aware that Nature was enjoying a resurgence. Forests and grasslands covered every continent, and those who stayed behind had to carry guns to defend against wild beasts when they went out, but it was rumored that they lived like kings, each with a vast estate and personal forests and lakes. The entire Earth was now only a single city in the Solar System Federation.

Cheng Xin and Cao Bin’s small dinghy was now at the outer edge of the Jovian cities. Before the immense, dark Jupiter, these cities appeared so small, so alone, like a few shacks at the foot of a gigantic cliff. From a distance, faint candlelight spilled out of them. Though tiny, they were the only hints of warmth, of home, in this endless frigidity and desolation, the goal of all weary travelers. Cheng Xin’s mind churned up a short poem she had read in middle school, a composition by a long-forgotten Chinese poet of the Republican era:

Bunker Era, Year 11 Lightspeed II

The final destination of Cheng Xin and Cao Bin was Halo City, a medium space city. Medium cities were space cities whose interior areas were below two hundred square kilometers but above fifty square kilometers. Typically, these cities were mixed within formations of large cities, but two of the medium cities, Halo City and Lightspeed II, were situated far from the Jovian city cluster, almost outside the protection of Jupiter’s shadow.

Before arriving at Halo City, the dinghy passed by Lightspeed II. Cao Bin told Cheng Xin that Lightspeed II used to be a science city and was one of the two research centers studying how to lower the speed of light to achieve the black domain state, but it had been abandoned. Cheng Xin was very interested and wanted to stop for a visit. Reluctantly, Cao Bin turned the dinghy in that direction.

“Why don’t we just take a look from the outside?” Cao Bin said. “It’s best not to go in.”

“Is it dangerous?”

“Yes.”

“But we went inside Pacific I, which was also dangerous.”

“It’s not the same. There’s no one inside Lightspeed II. It’s a… ghost city. At least, that’s what everyone says.”

As the dinghy approached, Cheng Xin realized that the city really was in ruins. It didn’t spin, and the exterior appeared broken and cracked. In some places, the skin of the city had been ripped open, revealing the structural frame underneath. As she surveyed the giant ruin illuminated by the searchlights of the dinghy, Cheng Xin felt awe as well as terror. She thought of the ruin as a beached whale. It had lain there for eons, until all that was left was cracked skin and bones, and life had long ago drained away. She seemed to be looking at something even older than the Acropolis of Athens, with even more secrets.

They slowly approached a large crack, several times as wide as the body of their dinghy. The beams in the structural frame were also bent and twisted, opening up a way to the interior. The beam of the searchlight shone in so that Cheng Xin could see the distant “ground,” which was completely bare. After the dinghy descended a short distance into the interior of the space city, it stopped and swept the searchlight about them. Cheng Xin saw that the “ground” was bare in every direction. Not only were there no buildings, there wasn’t anything at all to indicate that people had once lived here. The crisscrossing beams forming the frame for the city were visible on the “ground.”

“Is it just an empty shell?” Cheng Xin asked.

“No.”

Cao Bin looked at Cheng Xin for a few seconds, as if assessing her courage. Then he reached out and shut off the searchlights.

At first, all Cheng Xin could see was darkness. Starlight spilled in from the crack in front, as though she was gazing up at the sky through a broken roof. Eventually, her eyes adjusted to the dark, and she realized that the interior of the ruined space city wasn’t entirely dark, but was illuminated with a faint, flickering blue light. Cheng Xin shivered. She forced herself to calm down and looked for the source. The blue glow came from the center of the interior of the space city.

The light source blinked without pattern, like a twitching eye. The empty ground was filled with strange shadows, like a desolate wasteland illuminated by flashes of lightning on the horizon at night.

“The light is caused by space dust falling into the black hole,” Cao Bin said, pointing in the direction of the light source. He was trying to relieve some of Cheng Xin’s terror.

“There’s a black hole over there?”

“Yes. It’s about… no more than five kilometers from here. A microscopic black hole with a Schwarzschild radius of twenty nanometers and a mass equivalent to Leda, the Jovian moon.”

In this phosphorescent blue glow, Cao Bin told Cheng Xin the story of Lightspeed II and 高 Way.[7]

The research into lowering the speed of light through vacuum began at about the same time as the Bunker Project. As the Black Domain Plan was the second path for human survival, the international community devoted enormous resources to it, and the Bunker Project even built a large space city as a research center devoted to the subject—that would be Lightspeed I, located in the Saturn cluster. But sixty years of extensive research yielded no breakthroughs, and not even much advancement in theoretical foundation.

Lowering the speed of light through a medium wasn’t particularly difficult. As early as 2008 C.E., researchers had succeeded in lowering the speed of light through a medium to an incredible seventeen meters per second in a laboratory setting. But this was fundamentally different from lowering the speed of light through vacuum. The former only required causing the atoms in the medium to absorb and re-emit the photons—light continued to travel at its usual speed between atoms. This wasn’t useful for the Black Domain Plan.

The speed of light through vacuum was one of the fundamental constants of the universe. Altering it was equivalent to altering the laws of physics. Thus, lowering the speed of light required breakthroughs in fundamental physics—and considerable serendipity. After sixty years, the only substantive result of basic research was the creation of the circumsolar particle accelerator. This, in turn, led to the success of the largest project under the Black Domain Plan: the Black Hole Project.

Scientists had tried all kinds of extreme physical techniques in their efforts to alter the speed of light. Once, the strongest artificial magnetic field had been used. But the best way to influence light in vacuum was through a gravity field. Since it was extremely difficult to generate a local gravity field in a laboratory setting, the only path forward seemed to be a black hole. The circumsolar particle accelerator was capable of creating microscopic black holes.

The head of the Black Hole Project was 高 Way. Cao Bin had worked with him for a few years. He could not hide his complex feelings about the man as he described him to Cheng Xin.

“The man suffered from severe autism—no, I’m not talking about some kind of lonely genius choosing to isolate himself, but a real mental condition. He was extremely closed off and had trouble communicating with anyone, and he had never even touched a woman. His extraordinary professional success would only be possible in this age, but despite his accomplishments, most of his supervisors and colleagues thought of him as merely a high-powered intelligence battery. He was tortured by his illness and tried to change himself, and in this, he was different from other geniuses.

“Starting from, oh, I think the eighth year of the Broadcast Era, he dedicated himself to the theoretical study of lowering the speed of light. Over time, I think he began to develop a strange identification between the speed of light and his own personality—if he could change the speed of light, then it was the same as changing himself.

“But the speed of light through vacuum really was the most stable thing in the cosmos. Research into lowering the speed of light resembled torturing light without regard for consequences. People tried to do everything with light: strike it, twist it, break it, dissect it, stretch it, crush it, even destroy it—but the result was, at most, a change in its frequency in vacuum. But the speed of light remained unchanged, like an unscalable wall. After all these decades, theoreticians and experimenters alike were in despair. There was a saying: If there really were a Creator, the only thing He welded shut in all Creation was the speed of light.

“For 高 Way, the despair had yet another layer. By the time I went into hibernation, he was almost fifty. He had still never been with a woman, and he thought of his own fate as being as resistant as the speed of light; he became even more withdrawn and solitary.

“The Black Hole Project began in Year 1 of the Bunker Era and lasted eleven years. The planners did not invest much hope in it. Both theoretical calculations and astronomical observations had indicated that even black holes could not change the speed of light. These demons of the universe could only use their gravity fields to change the path of light and its frequency, not affecting the speed of light through vacuum one iota. However, to continue the research for the Black Domain Plan, it was necessary to create experimental conditions with superpowerful gravity fields, which depended on black holes. In addition, since a black domain is in essence a large-scale reduced-lightspeed black hole, perhaps close-range observation of a microscopic regular-lightspeed black hole would yield unexpected insights.

“The circumsolar particle accelerator was capable of producing microscopic black holes rapidly, but these tiny black holes also evaporated very quickly. To produce a stable black hole, a microscopic black hole was guided out of the accelerator as soon as it was produced, and then injected into Leda.

“Leda was Jupiter’s smallest moon, with a mean radius of only eight kilometers. It was nothing more than a large rock. Before making the black hole, they had lowered the moon from its high orbit and turned it into a body orbiting the Sun in parallel with Jupiter, like the city cluster. However, unlike the city cluster, it was located at the Sun-Jupiter L2 Lagrangian point, which is where we are now. This allowed it to maintain a stable distance from Jupiter without having to constantly adjust its position. At the time, this was the most massive body humans had managed to move through space until then.

“After the microscopic black hole was injected into Leda, it began to absorb mass and rapidly grow. At the same time, the intense radiation generated by material falling into the black hole melted the surrounding rock. Soon, the eight-kilometer-radius Leda melted entirely, and the potato-shaped rock turned into a red-glowing ball of lava. The lava ball shrank slowly, but glowed brighter and brighter, until it finally disappeared with a blinding flash. Observation showed that other than a small amount of material ejected by the radiation, most of the mass of Leda had been absorbed by the black hole. The black hole remained stable, and its Schwarzschild radius, or event horizon radius, had grown from the size of a fundamental particle to twenty-one nanometers.

“They constructed a space city around the black hole—that’s Lightspeed II. The black hole was suspended in the middle of the space city, which was empty, didn’t spin, and whose interior was a vacuum connected to space. It was, in essence, a giant container for the black hole. Personnel and equipment could be brought into the city to study the black hole.

“The research continued for many years. This was the first time that humans could study a black hole specimen in laboratory conditions, and many discoveries were made that helped with the development of theoretical physics and fundamental cosmology. But none of these results helped with the task of lowering the speed of light in vacuum.

“Six years after the commencement of studies on the black hole specimen, 高 Way died. According to the official account of the World Academy of Sciences, he was accidentally ‘sucked into the black hole’ during an experiment.

“Anyone with some basic scientific background knows that the probability that Gao was ‘sucked’ into the black hole was practically nonexistent. The reason that black holes are traps from which even light cannot escape isn’t because their overall gravitational power is overwhelming—though a large black hole formed by the collapse of a star does possess immense overall gravity—but due to the density of their gravitational fields. From a distance, the total gravity of a black hole is no different from the gravity of a quantity of normal matter of equivalent mass. If the Sun collapsed into a black hole, the Earth and the other planets would still continue on in their orbits without being sucked in. It’s only when you got very close to the black hole that its gravity displayed strange behavior.

“Inside Lightspeed II, there was a protective net around the black hole with a radius of five thousand meters. Research personnel were forbidden to enter. Since the radius of Leda was originally only eight thousand meters, the black hole’s gravity at this distance was not much greater than the gravity on the surface of the original Leda. It’s not a very powerful pull—a person standing there was essentially weightless, and could easily escape using the thrusters on their space suit. Thus, Gao couldn’t have been ‘sucked’ in.

“Ever since the stable black hole specimen was obtained, 高 Way was infatuated with it. After struggling against the speed of light for so many years and not being able to alter even a single one of the many digits in this constant that came close to three hundred thousand, Gao was agitated and filled with a sense of failure. As the constancy of the speed of light was one of the fundamental laws of nature, he had come to despise the laws of nature, as well as being afraid of them. But now, in front of his eyes, was something that had compressed Leda into twenty-one nanometers. Within its event horizon, in that space-time singularity, known laws of nature had no effect.

“高 Way often hung against the protective net and stared for hours at the black hole five kilometers away. He watched its luminescence—like we’re doing now—and sometimes claimed that the black hole was talking to him, that he could decipher the message of its flickering light.

“No one saw the process of Gao’s disappearance, and if there was a recording, it’s never been released. He was one of the Black Hole Project’s principal physicists, and he had the password to open the protective net. I’m certain that he went in and drifted toward the black hole until he was too close to return…. He probably wanted to get a close-up look at the object of his infatuation, or perhaps he wanted to enter into that singularity where the laws of nature no longer mattered, so that he could escape all this.

“What happened after 高 Way was sucked in was almost too strange to describe. Scientists observed the black hole via remote-controlled microscopes, and discovered that at the black hole’s event horizon—that’s the surface of that tiny sphere with a diameter of twenty-one nanometers—there was the figure of a person. It was 高 Way passing through the event horizon.

“Under general relativity, a distant observer would see a clock near the event horizon slow down, and the process of 高 Way falling toward the event horizon would also slow down and stretch into infinity.

“But within 高 Way’s own frame of reference, he had already passed through the event horizon.

“Even more oddly, the figure’s proportions were normal. Perhaps it was because the black hole was so small, but tidal forces did not seem to be at work. He had been compressed into the nanometer range, but space there was also extremely curved. More than one physicist believed that the body structure of 高 Way wasn’t harmed at the event horizon. In other words, he’s probably still alive at this moment.

“And thus the life insurance company refused to pay out, although 高 Way had passed through the event horizon in his frame of reference, and should now be dead. But the insurance contract was made within the frame of reference of our world, and from this perspective, it is impossible to prove that 高 Way is dead. It’s not even possible to begin the settlement process. Insurance claims settlement can only occur after the conclusion of an accident, but as 高 Way is still falling toward the black hole, the accident isn’t over, and will never be over.

“A woman then sued the World Academy of Sciences and demanded that the academy cease all further research on this black hole specimen. By that point, distant observation was unlikely to yield any further results. In order to be useful, future research would have to manipulate the black hole in some way, such as sending experimental objects into the black hole, which would generate massive amounts of radiation, and might disturb space-time in the vicinity of the event horizon. If 高 Way were still alive, these experiments might endanger his life. The woman didn’t win her suit, but for a variety of reasons, research on this black hole stopped, and Lightspeed II was abandoned. Now we can only wait for this black hole to evaporate, which is estimated to take another half century.

“However, we now know that at least one woman did love 高 Way, though he never knew it. Later, that woman still came here regularly and tried to send radio or neutrino messages at the black hole. She even wrote her love in big letters and posted it against the protective net, hoping that the falling 高 Way could see it. But based on his own frame of reference, he had already passed through the event horizon into the singularity…. It’s a complicated matter.”

Cheng Xin stared at the blue phosphorescence far away in the darkness. She now knew that there was a man there, a man who was falling forever, at the event horizon where time stopped. Such a man was still alive when viewed from this world, but had already died in his own world…. So many strange fates, and so many unimaginable lives….

Cheng Xin now felt the flickering black hole was really sending out a message, even more like someone blinking. She pulled her gaze back, feeling as empty in her heart as this ruin in space. Softly, she said to Cao Bin, “Let’s go to Halo City.”

Bunker Era, Year 11 Halo City

As they approached Halo City, Cheng Xin and Cao Bin’s dinghy encountered the Federation Fleet’s blockade line. More than twenty stellar-class warships surrounded Halo City, and the blockade had lasted two weeks already.

The stellar-class ships were immense, but next to the space city they appeared as tiny skiffs around a giant ocean liner. The Federation Fleet had sent the bulk of their ships to enforce this blockade of Halo City.

After the two Trisolaran Fleets had disappeared in the depths of space and the Trisolarans lost all contact with humankind, the extraterrestrial threats facing humanity took on an entirely new form. Fleet International, which had been formed to combat the Trisolaran invasion, lost its reason for existence and gradually diminished in relevance until it was finally dissolved. The Solar System Fleet that had belonged to Fleet International became the property of the Solar System Federation. This was the first time in human history where a unified world government controlled the majority of humanity’s armed forces. Since it was no longer necessary to maintain a large space force, the fleet’s size was drastically reduced. After the commencement of the Bunker Project, most of the then-extant hundred-plus stellar-class warships were converted for civilian use. After they were disarmed and their ecological cycling systems removed, they became interplanetary industrial transports for the Bunker Project. Only about thirty stellar-class warships remained in service. Over the last sixty-plus years, no new warships had been built because large warships were extremely expensive. It took the same amount of investment to build two or three stellar-class warships as it did to build a large space city. Moreover, there was no need for new warships. Most of the Federation Fleet’s efforts were devoted to building the advance warning system.

The dinghy stopped advancing as it received the blockade order. A military patrol boat sailed toward it. It was very small, and from a distance Cheng Xin could only see the glow from its thrusters—its hull could be seen only once it got closer. When the patrol boat docked with the dinghy, Cheng Xin had a chance to look at the uniformed men inside it. Their military uniforms were very different from those of the last era and seemed to hearken to the styling of an earlier age. The uniforms had fewer space-based characteristics and looked more like the uniforms of old Earth-based armies.

The man who drifted over after the two vessels docked was middle-aged and dressed in a suit. Even in weightlessness, he moved gracefully and calmly, not appearing ill at ease at all in the cramped space that was meant only for two.

“Good day. I’m Blair, special envoy of the Federation president. I’m about to try, for the last time, to negotiate with Halo City’s city government. I could have talked to you from my ship, but out of respect for Common Era customs, I decided to come here in person.”

Cheng Xin noticed that even the politicians of this age had changed. The assertive and outspoken mannerisms of the last era had been replaced by prudence, restraint, and politeness.

“The Federation Government has announced a total blockade of Halo City, and no one is permitted to enter or leave. However, we know that the passenger here is Dr. Cheng Xin.” The envoy nodded at her. “We give you permission to pass and will assist your entrance into Halo City. We hope that you will use your influence to persuade the city government to cease their deranged, illegal resistance, and prevent the situation from deteriorating further. I am expressing the wishes of the Federation president.”

The special envoy waved his hand and opened up an information window. The Federation president appeared in the window. In the office behind him were the flags of the various cities of the Bunker World, none of which were familiar to Cheng Xin. Nation states had disappeared along with their flags. The president was an ordinary-looking man of Asian descent. His face looked tired, and after nodding a greeting at Cheng Xin, he said, “Envoy Blair is right. This is the will of the Federation Government. Mr. Wade said that the final decision rests with you, an assertion that we do not fully believe. But we wish you the best of success. I’m glad to see you still looking so young. Although, for this matter, perhaps you’re too young.”

After the president disappeared from the window, Blair said to Cheng Xin, “I know that you already have some understanding of the situation, but I’d still like to give you an overall explanation. I’ll strive to be objective and fair.”

Cheng Xin noticed that both the envoy and the president spoke only to her, ignoring Cao Bin’s presence, indicating by this omission the deep enmity they felt toward him. As a matter of fact, Cao Bin had already explained the situation to her in detail, and the envoy’s account wasn’t too different.

After Thomas Wade took over the Halo Group, the company became a key contractor in the Bunker Project. Within eight years, it had grown tenfold and become one of the largest economic entities in the world. Wade himself was not an extraordinary entrepreneur; indeed, he was not even as skilled as 艾 AA at managing the company’s operations. The company’s growth was the result of the new management team he put in place. He personally did not participate in the running of the company and had little interest in it, but much of the profit generated by the company was taken by him and reinvested in the development of lightspeed spaceflight.

As soon as the Bunker Project began, the Halo Group constructed Halo City as a research center. The Sun-Jupiter L2 Lagrangian point was chosen as the ideal space to set up Halo City in order to eliminate the need for city thrusters and the consumption of resources for position maintenance. Halo City was the only space science city outside the jurisdiction of the Federation Government. While Halo City was being constructed, Wade also began the construction of the circumsolar particle accelerator, a project that was dubbed “The Great Wall of the Solar System” because it enclosed the Sun in a ring.

For half a century, the Halo Group devoted itself to basic research for lightspeed spaceflight. Ever since the Deterrence Era, large companies had often engaged in basic research. In the new economic system, basic research could generate enormous profits. Thus, the behavior of the Halo Group wasn’t too unusual. The Halo Group’s ultimate goal of constructing lightspeed spaceships was an open secret, but as long as it stuck to basic research, the Federation Government could not accuse it of violating the law. However, the government continued to be suspicious of the Halo Group, and investigated it multiple times. For half a century, the relationship between the company and the government was basically cordial. Since lightspeed ships and the Black Domain Plan called for much of the same basic research, the Halo Group and the World Academy of Sciences maintained a good collaborative working relationship. For instance, the Academy’s Black Hole Project used the Halo Group’s circumsolar particle accelerator to produce its black hole specimen.

However, six years ago, the Halo Group had suddenly announced its plan to develop curvature propulsion ships. Such open defiance caused an uproar in the international community. Thereafter, conflict between the Halo Group and the Federation Government never ceased. After multiple rounds of negotiations, the Halo Group promised that when the curvature propulsion drive was ready for trials, the testing site would be at least five hundred AU from the Sun so as to avoid exposing the location of Earth civilization with the trails. But the Federation Government felt that the very development of lightspeed ships was a gross violation of the laws and constitution of the Federation. The danger of lightspeed ships lay not only in the trails, but also in upsetting the new social stability in the Bunker World, a prospect that could not be tolerated. A resolution was passed to authorize the government takeover of Halo City and the circumsolar particle accelerator, and to put a complete stop to the Halo Group’s theoretical research and technical development in curvature propulsion. Thereafter, the Halo Group’s behavior would be subjected to close monitoring.

In response, the Halo Group declared independence from the Solar System Federation. Thus, the conflict between the Halo Group and the Federation escalated yet further.

The international community did not take the Halo Group’s declaration of independence too seriously. As a matter of fact, after the commencement of the Bunker Era, conflicts between individual space cities and the Federation Government were not infrequent. For instance, two space cities in the distant city clusters near Uranus and Neptune, Africa II and Indian Ocean I, had declared independence in the past, but nothing had ultimately come of those efforts. Although the Federation Fleet was nowhere near the size it had been in the past, it was still an overwhelming force if applied against individual space cities. By law, space cities were not allowed to possess their own independent armed forces—they could only have limited national guards who had no capacity for space warfare at all. The economy of the Bunker World was also highly integrated such that no individual space city could survive a blockade longer than two months.

“On this point, I can’t understand Wade either,” said Cao Bin. “He’s a man with foresight, and mindful of the big picture, and he never takes a step without having thought through the consequences. So why declare independence? It seems idiotic to provide the Federation Government with an excuse to take over Halo City by force.”

The envoy had already left, and the dinghy, now occupied only by Cheng Xin and Cao Bin, continued on course to Halo City. A ring-shaped structure appeared in space ahead, and Cao Bin ordered the dinghy to approach it and decelerate. The smooth metallic surface of the ring reflected the stars as long streaks and distorted the image of the dinghy, bringing to mind the Ring that Blue Space and Gravity had encountered in four-dimensional space. The dinghy stopped and hovered next to the ring. Cheng Xin estimated that the ring’s diameter was about two hundred meters across, and the band about fifty meters thick.

“You’re looking at the circumsolar particle accelerator,” Cao Bin said, his tone awed.

“It’s… rather small.”

“Oh, sorry; I wasn’t clear. This is but one of the coils in the particle accelerator. There are thirty-two hundred coils like this, each about one point five million kilometers apart, forming a large circle around the Sun in the vicinity of Jupiter’s orbit. Particles pass through the center of these coils, where they’re accelerated by the force field generated by the coil toward the next coil, where they’re accelerated again…. A particle might travel around the Sun multiple times during the process.”

When Cao Bin had spoken to Cheng Xin about the circumsolar particle accelerator in the past, she had always pictured it as a giant doughnut hanging in space. But in reality, to build a solid “Great Wall” around the Sun, even within the orbit of Mercury, would have been an impossible feat approaching the level of God’s Engineering Project. Cheng Xin finally realized that while an enclosed tubular ring was necessary for terrestrial particle accelerators to maintain vacuum, it was not necessary in the vacuum of space. The particles being accelerated could simply fly through space, being accelerated by one coil after another. Cheng Xin couldn’t help turning to look past the coil for the next one.

“The next coil is one point five million kilometers away, four or five times the distance from the Earth to the moon. You can’t see it,” Cao Bin said. “This is a supercollider capable of accelerating a particle to the energy level of the big bang. Ships are not allowed anywhere near the orbit of the accelerator. A few years ago, a lost freighter drifted into the orbit by mistake and was hit by a beam of accelerated particles. The ultrahigh-energy particles struck the ship and produced high-energy secondary showers that vaporized the ship and its cargo of millions of tons of mineral ore in an instant.”

Cao Bin also told Cheng Xin that the circumsolar particle accelerator’s chief designer was Bi Yunfeng. Of the past sixty-plus years, he had spent thirty-five of them working on this project and hibernated for the rest. He had been awakened last year, but was much older than Cao Bin now.

“The old man’s lucky, though. He had worked on a terrestrial accelerator back during the Common Era, and now, three centuries later, he got to build a circumsolar particle accelerator. I’d call that a successful career, wouldn’t you? But he’s a bit of an extremist, and a fanatic supporter of Halo City independence.”

While the public and the politicians opposed lightspeed ships, many scientists supported the effort. Halo City became a holy site for scientists who yearned for lightspeed spaceflight and attracted many excellent researchers. Even scientists working within the Federation scientific establishment often collaborated with Halo City—openly or in secret. This caused Halo City to be on the cutting edge in many areas of basic research.

The dinghy left the coil and continued its voyage. Halo City was straight ahead. This space city was built along the rarely seen wheel plan. The structure provided strength but had little interior volume, lacking “world-sense.” It was said that the inhabitants of Halo City did not need world-sense, because for them, the world was the entire universe.

The dinghy entered the axis of the giant wheel, where Cheng Xin and Cao Bin had to enter the city through an eight-kilometer spoke. This was one of the least convenient aspects of a wheel plan. Cheng Xin was reminded of her experience more than sixty years ago at the terminal station of the space elevator, and she thought about the great hall that reminded her of an old train station. But the feeling here was different. Halo City was more than ten times larger than that terminal station, and the interior was rather spacious and didn’t look run-down.

On the escalator of the spoke, gravity gradually set in. By the time it reached 1G, they were in the city proper. The science city was made up of three parts: the Halo Academy of Sciences, the Halo Academy of Engineering, and the Control Center for the circumsolar particle accelerator. The city was in fact a ring-shaped tunnel thirty-some kilometers in length. Although it wasn’t nearly as open or spacious as the large, hollow shells of other cities, one didn’t feel claustrophobic, either.

Cheng Xin didn’t see any motor vehicles in the city at first. Most residents got around on bicycles, many of which were parked on the side of the road for anyone to use. But a small convertible motor vehicle came to pick up Cheng Xin and Cao Bin.

Since the simulated gravity in the ring pulled toward the outer rim, the city was built along that surface. A holographic image of blue sky with white clouds was projected onto the inner rim, which made up some for the lack of world-sense. A flock of twittering birds flitted overhead, and Cheng Xin noticed that they were not holograms, but real. Here, Cheng Xin felt a sense of comfort that she had not experienced in the other space cities. There were plenty of trees and lawns everywhere. None of the buildings was very tall. Those belonging to the Academy of Sciences were painted white, while those belonging to the Academy of Engineering were painted blue, but each building was unique. The delicate buildings were half-hidden by the green plants, and made her feel as though she were on a college campus.

Cheng Xin saw an interesting sight on her drive. There was a ruin like an ancient Greek temple. On a stone platform stood a few broken Greek columns covered with climbing ivy. In the middle of the columns was a fountain shooting a column of limpid water merrily into the sunlight. A few casually dressed men and women were leaning against the columns or lying on the lawn next to the fountain, lazing about comfortably. They seemed not to care that the city was under siege by the Federation Fleet.

A few statues were scattered on the lawn next to the ruin. Cheng Xin’s attention was drawn to one of the statues: A gauntleted hand was picking wreaths woven with stars out of a pool with a sword, and flowing water dripped from the wreaths continuously. This sight triggered something deep in Cheng Xin’s memory, but she couldn’t recall where exactly she had seen it before. She gazed at the statue from the motorcar until it disappeared.

The car stopped in front of a blue building. It was a laboratory marked with a sign: “Academy of Engineering, Basic Technology 021.” Cheng Xin saw Wade and Bi Yunfeng on the lawn in front of the laboratory.

Wade had never entered hibernation since taking over the Halo Group, and was now 110 years old. He kept his hair and beard short, but both were now white as snow. He didn’t use a cane, and his stride was steady, but his back was a bit bent, and one of his sleeves still hung empty. In the moment they locked gazes, Cheng Xin understood that time had not defeated this man. What was at his core had not been worn away by the passing years, but had only become more prominent—like a rock revealed after the snow and ice had melted away.

Bi Yunfeng should be much younger than Wade, but he looked older. He was very excited to see Cheng Xin and seemed eager to show her something.

“Hello, little girl,” Wade said. “I’m now three times your age.” His smile still couldn’t make Cheng Xin warm, but it no longer felt as cold as ice water.

Cheng Xin faced these two old men with mixed feelings. They had struggled for their ideals for more than sixty years and were now near the end of their lives’ journeys. She, on the other hand, had gone through so many trials after awakening for the first time during the Deterrence Era—but in reality, she had spent no more than four years out of hibernation. She was now 33, still a young woman in this era where average life expectancy was 150.

Cheng Xin greeted the two, and then no one wasted time by saying more. Wade led Cheng Xin into the laboratory with Bi Yunfeng and Cao Bin following. They entered a spacious, windowless hall. The familiar acrid odor of static told Cheng Xin they were in a sophon-free room. After more than sixty years, people still could not be sure that the sophons had left the Solar System, and maybe they’d never be sure. The hall must have been filled with instruments and equipment not long ago, but now all the lab equipment was scattered in a chaotic pile next to the walls, as though it had been moved away in a hurry to clear out the center. In the middle of the hall was a single machine. The surrounding chaos and the emptiness in the center displayed an irrepressible excitement, as though a team of treasure hunters had suddenly found a priceless artifact, tossed their tools to the side, and carefully moved their prize to the center of the open space.

The machine’s complex structure reminded Cheng Xin of a tokamak from the Common Era, but miniaturized. The bulk of the machine consisted of a sphere bisected horizontally by a flat black metallic plane that extended several meters over the edge of the sphere. The plane, holding up the sphere at about waist-height, also served as a lab bench with sturdy legs. The surface of the bench was mostly empty save for a few tools and manipulators attached to telescoping arms.

The metal hemisphere below the bench was studded with tubes of various thicknesses, all aimed at the invisible center of the sphere, causing the machine to look like a naval mine studded with Hertz horns. Apparently, the arrangement was designed to concentrate some kind of energy at the center.

The hemisphere above the bench, in contrast, was made of transparent glass. The two hemispheres together formed a whole divided by the metal plane, contrasting simple transparency with complex opacity.

Looking down through the glass dome, Cheng Xin could see a small rectangular metallic platform whose sides measured only a few centimeters, about the size of a pack of cigarettes, and whose surface was smooth and reflective like a mirror. The platform under the glass dome was like a tiny, delicate stage; and the complicated mechanism below the plane the orchestra that would accompany the performance, though it was unimaginable what that performance would be.

“Let’s allow a physical part of you to experience this grand moment,” Wade said. Bi Yunfeng lifted the glass dome as Wade walked over to Cheng Xin and held up a pair of scissors. Cheng Xin tensed, but did not shy away. Carefully, assisted by a tool on the platform, Wade lifted a strand of her hair and cut off a small section at the end. He held the hair clipping with the tool, examined it, and concluded it was still too long. He cut the clipping in half so that the remaining piece was only about two or three millimeters long, almost invisible. Wade walked over to the side of the opened glass dome and carefully placed the hair on the smooth metal platform. Although Wade was over a hundred years of age and had only one hand, his movements were precise and steady, showing no tremors.

“Come, watch carefully,” Wade said.

Cheng Xin leaned down to look through the glass dome. She could see her hair resting against the smooth stage. There was a red line down the middle of the stage, and the hair was on one side of it.

Wade nodded at Bi Yunfeng, who opened a control window in the air and activated the machine. Cheng Xin looked down and saw that a few tubes connected to the machine began to glow red, reminding her of the glimpse she had caught of the inside of the Trisolaran spaceship. She heard a rumbling but didn’t feel any heat. She returned her gaze to the small platform and felt some invisible disturbance spread out from the platform, brushing across her face like a light breeze. She couldn’t be sure it wasn’t just an illusion.

She saw that her hair had moved to the other side of the red line, but she hadn’t seen it move.

After another series of rumblings, the machine stopped.

“What did you see?” Wade asked.

“You spent half a century to move a three-millimeter section of hair two centimeters,” said Cheng Xin.

“It was curvature propulsion,” Wade said.

“If we used the same technique to continue to accelerate the hair, it would be moving at lightspeed in about ten meters,” Bi Yunfeng said. “Of course we can’t achieve this now, and we dare not try it here. If we did, this bit of hair, moving at lightspeed, would destroy Halo City.”

Cheng Xin pondered the strand of hair that had been moved two centimeters by curving space. “You are saying that you’ve invented gunpowder and managed to make a firecracker, but the ultimate goal is to make a space rocket. A thousand years may separate those two achievements.”

“Your analogy is flawed,” Bi Yunfeng said. “We have invented the equation relating energy to mass, and we’ve discovered the principle of radioactivity. The ultimate goal is to make the atom bomb. Only a few decades divide those two achievements.”

“In fifty years, we should be able to construct curvature propulsion spaceships capable of lightspeed flight. This will require massive amounts of technical testing and development work. We have to lay our cards on the table now so that the government can back off and give us the environment necessary to carry out these tasks.”

“But your current approach will make you lose everything.”

“Everything depends on your decision,” Wade said. “You must think that we’re helpless against the power of that fleet out there. Not so.” He gestured at the door. “Come in.”

A group of forty or fifty armed men filed in and soon filled the hall. They were all young men dressed in black space camouflage, and their presence seemed to make the hall dimmer. They wore military-issue lightweight space suits that seemed no different from ordinary military uniforms, but they could enter space as soon as they put on helmets and life-support backpacks. Cheng Xin was astonished, however, to see the weapons they carried: rifles, from the Common Era. Perhaps they were newly made, but the design was ancient and entirely mechanical, with manual bolts and triggers. The ammunition they carried confirmed this: Everyone wore two crossed bandoliers filled with glistening yellow cartridges.

To see these men in this age was akin to seeing a group of men armed with bows and swords during the Common Era. This was not to say that the fighters did not appear visually intimidating. Cheng Xin felt the presence of the past not only because of their ancient weapons, but also their appearance. They displayed a trained esprit de corps: they were uniform not only in dress and equipment, but also in their spirit. The men appeared tough and strong, with muscles bulging beneath their thin space suits. The gazes and expressions on their bold, angular faces were very similar: an indifferent, metallic grimness that viewed life as cheap as grass.

“This is our city self-defense force.” Wade waved at the assembled men. “They are all we have to protect Halo City and the ideal of the lightspeed ship. You can see almost all of them here—there are a few more outside, but the total is no more than a hundred. As for their equipment—” Wade took a rifle from one of the soldiers and pulled the bolt. “You can trust your eyes: ancient weapons constructed of modern materials. The bullets do not rely on gunpowder as the propellant and have much better range and precision compared to genuine ancient weapons. In space, these rifles can hit a ship from two thousand kilometers away, but fundamentally, they’re primitive weapons. You must think this ridiculous, and I would, too, except for one thing.” He returned the rifle to the soldier and pulled one of the cartridges from his bandolier. “As I said, the cartridges are basically of ancient design, but the bullets are new. So new, in fact, that they might as well come from the future. The bullet is a superconducting container and the interior is a pure vacuum. A magnetic field suspends a small ball in the middle to prevent it from contacting the bullet’s body. The ball is made of antimatter.”

Bi Yunfeng’s voice was filled with pride. “The circumsolar particle accelerator was not only used for basic research experiments, but also to produce antimatter. In the last four years, we’ve used it to make antimatter practically the entire time. We now possess fifteen thousand bullets of this design.”

The primitive-seeming cartridge held in Wade’s hand now caused Cheng Xin to suffer chills. She now worried about the reliability of the containment magnetic field within that superconducting bullet: a single malfunction would be enough to cause the complete destruction of Halo City in a brilliant flash. She looked at the golden bandoliers hanging over the chests of every soldier: These were the chains of the god of Death. A single bandolier possessed enough power to destroy the entire Bunker World.

Wade continued, “We don’t even have to go into space to attack. We just have to wait until the fleet approaches the city. We can shoot dozens or even hundreds of bullets at each of the twenty or so ships—a single hit is enough to destroy it. Although the tactic is primitive, it’s effective and flexible. A single soldier with a gun is a fighting unit capable of threatening an entire warship. Also, we have agents in other space cities with handguns.” He returned the cartridge to the soldier’s bandolier. “We don’t want war. During the final negotiations, we’ll show our weapons to the Federation envoy and explain our tactics. We hope the Federation Government will weigh the costs of war and abandon their threat against Halo City. We’re not asking for much, only to build a research center several hundred AU from the Sun devoted to curvature propulsion testing.”

“But if we go to war, can you guarantee victory?” Cao Bin asked. He had not spoken so far. Unlike Bi Yunfeng, he apparently was not in favor of war.

“No,” Wade answered calmly. “But neither can they. We can only try.”

As soon as Cheng Xin saw the antimatter bullet in Wade’s hand, she knew what she must do. She wasn’t too worried about the Federation Fleet—she believed that they’d come up with ways to deal with this tactic. Her mind was focused on only one thing:

Also, we have agents in other space cities with handguns.

If war were to erupt, any of the guerrilla fighters hidden in the other space cities could casually shoot one of the antimatter bullets at the ground and the explosion of matter-antimatter annihilation would instantaneously tear apart the thin shell of the city and incinerate everything within. Next, the spinning space city would break into fragments and millions would die.

Space cities were as fragile as eggs.

Wade had not explicitly said that he would attack the space cities, but he also hadn’t said he wouldn’t. She again saw Wade aiming a gun at her 133 years ago—an image which had been branded into her heart. She didn’t know how cold a man would have to be to make such a decision, but the core of this man was the utter madness and coldness brought about by extreme rationality. She seemed to see again the young Wade from three centuries ago, screaming like a crazy beast: “Advance, advance without regard for consequences!”

Even if Wade did not want to attack the space cities, what if others on his force did?

As if confirming Cheng Xin’s fear, a soldier spoke to her. “Dr. Cheng, please be assured that we will fight to the end.”

Another soldier spoke up. “We are not fighting for you, for Mr. Wade, or this city.” He pointed upwards, and fire seemed to light up his eyes. “Do you know what they’re trying to take away from here? Not the city or lightspeed ships, but the entire universe outside the Solar System! There are billions and billions of new worlds out there, but they won’t let us go; they want to lock us and our descendants in this prison, a prison fifty astronomical units in radius called the Solar System. We are fighting for freedom, for a chance to live as free men in the universe. Our cause is the same as every ancient struggle for freedom. We will fight to the very last. I speak for everyone in the self-defense force.”

The other soldiers nodded at Cheng Xin, their eyes grim and cold.

In the years to come, Cheng Xin would recall the soldier’s words countless times. But at this moment, they did not move her. She felt the world going dark, and she was mired in terror. She felt as though she was again standing in front of the UN headquarters, holding that baby from more than 130 years ago. She felt the baby in her arms was facing a flock of hungry wolves, and she had to protect the child at all costs.

“Will you keep your promise?” she asked Wade.

Wade nodded. “Of course. Why else would I ask you to come here?”

“Then stop all preparation for war and cease all resistance. Turn over all antimatter bullets to the Federation Government. Order those agents you’ve sent to the other cities to do the same immediately!”

The soldiers gazed at Cheng Xin, as if trying to burn her to a crisp with their eyes. The power differential between the two sides was overwhelming. She was faced with a cold machine of war. Every man carried more than a hundred hydrogen bombs, and, led by a strong, mad leader, they formed a powerful black wheel capable of crushing all resistance. She was nothing more than a blade of grass in front of this giant wheel, not able to even slow down its progress. But she had to do what she could.

However, things did not develop as she expected. The gazes of the soldiers moved away from her one by one, turning to Wade. The suffocating pressure seemed to let up gradually, but she still had trouble breathing. Wade continued to look at the curvature propulsion platform under the glass dome holding up Cheng Xin’s hair as though gazing at a sacred altar. Cheng Xin could imagine that Wade had once gathered his warriors around this altar to prophesy war.

“Why don’t you think about it some more?” Wade said.

“There’s no need.” Cheng Xin’s voice was like iron. “I have made my final decision. Cease all resistance, and turn over all antimatter in Halo City.”

Wade lifted his head and looked at Cheng Xin with rarely seen helplessness and pleading. He spoke slowly. “If we lose our human nature, we lose much, but if we lose our bestial nature, we lose everything.”

“I choose human nature,” Cheng Xin said, looking around at everyone. “I believe you all will, as well.”

Bi Yunfeng was about to speak, but Wade stopped him. His eyes dimmed. Something had gone out in them, extinguished forever. The weight of years abruptly crushed him, and he appeared exhausted. He supported himself on the metal platform with his one hand and slowly sat down on a chair someone else brought over. Then he lifted his hand and pointed to the platform in front of him, keeping his eyes down. “Disarm. Leave all your ammunition here.”

No one moved at first. But Cheng Xin felt something soften. That dark force was dissipating. The soldiers looked away from Wade and no longer focused on a single point. Finally, someone walked over and placed two bandoliers on the platform. Though his movements were gentle, the metallic sound made by the cartridges scraping against the platform caused Cheng Xin to shudder. The bandoliers lay still on the platform like two gold-colored snakes. A second man walked over and deposited his bandoliers, then more. The platform was soon covered by a golden pile. After all the cartridges had been collected, the metallic noises stopped, and everything became quiet again.

“Order all of our agents in the Bunker World to disarm and surrender to the Federation Government,” Wade said. “The Halo City government will collaborate with the fleet to turn over the city. Do not take any drastic action.”

“All right,” someone answered. Deprived of their bandoliers, these men dressed in black space suits made the place even dimmer.

Wade gestured for the self-defense force to leave. They departed noiselessly, and the hall brightened as though a dark cloud had dissipated. Wade struggled to stand, walked around the pile of antimatter cartridges, and slowly opened the glass dome. He blew at the curvature propulsion platform and Cheng Xin’s hair disappeared. He closed the dome, turned to Cheng Xin, and smiled. “You see, I’ve kept my promise, little girl.”

After the Halo City Incident, the Federation Government did not immediately disclose the existence of antimatter weapons. The international community thought the event concluded as they had expected, and there wasn’t much reaction. As the creator of the circumsolar particle accelerator, the Halo Group enjoyed great prestige internationally, and public opinion was mostly forgiving of them, suggesting that there was no reason to pursue anyone legally, and Halo City should be allowed to self-govern again as soon as possible. As long as the Halo Group promised to never again engage in any research and development of curvature propulsion and submitted to Federation monitoring, it should be allowed to go on with its business.

But one week later, Federation Fleet Command revealed to the world the captured antimatter bullets. The pile of golden Death stunned everyone.

The Halo Group was declared an illegal organization, and the Federation Government confiscated all its property and took over the circumsolar particle accelerator. The Federation Fleet declared a long-term occupation of Halo City, and the Academies of Science and Engineering were dissolved. More than three hundred people, including Wade, the other leaders of the Halo Group, and the city self-defense force, were arrested.

In the subsequent trial in Federation court, Thomas Wade was convicted of crimes against humanity, war crimes, and violations of the laws prohibiting research into curvature propulsion. The sentence was death.

Cheng Xin went to a detention center located near the Supreme Federation Court in Earth I, the Solar System Federation’s capital, to see Wade one last time. They looked at each other through a transparent barrier and said nothing. Cheng Xin saw that this old man, 110 years old, was as placid as the puddle at the bottom of a well that was about to dry out. There would be no more ripples.

Cheng Xin passed the box of cigars she had bought in Pacific I through an opening in the barrier. Wade opened the box, took out three of the ten cigars, and pushed the box back through the opening.

“I won’t be able to use the rest,” he said.

“Tell me more about yourself. Your work, your life. I want to tell those who would come later about you,” Cheng Xin said.

Wade shook his head. “I am but one of the countless who have died and will die. What is there to tell?”

Cheng Xin knew that what divided them wasn’t just this transparent barrier, but also the deepest chasm in this world, a chasm that could never be bridged.

“Do you have anything to say to me?” Cheng Xin asked. She was surprised that she wanted to hear his answer.

“Thank you for the cigars.”

It took a long while before Cheng Xin understood that this was what Wade wanted to say to her. His last words. All his words.

They sat in silence, neither looking at the other. Time turned into a stagnant pool that drowned them. Then, the tremors of the space city adjusting its position returned Cheng Xin to reality. She stood up slowly and softly said good-bye.

Once she was outside the detention center, Cheng Xin picked out one of the cigars and borrowed a light from one of the guards. She took her first puff of a cigar in her life. Oddly, she didn’t cough. She watched the white smoke rise in the sunlight of the capital, watched it dissipate in her tear-filled vision like the three centuries she and Wade had lived through.

Three days later, a powerful laser vaporized Thomas Wade in one-ten-thousandth of a second.

Cheng Xin returned to Asia I’s hibernation center and awakened 艾 AA. They returned to the Earth.

They rode Halo back. After the Halo Group had been dissolved and its property confiscated, the Federation Government returned a small portion of the company’s vast wealth to Cheng Xin. The amount was about equal to the value of the Halo Group at the time Wade took over. It was still a large sum, though minuscule when compared to the total wealth of the vanished company. Halo was part of the property returned to Cheng Xin—though this was the third ship to bear that name. It was a small stellar yacht capable of seating up to three. The shipboard ecological cycling system was comfortable and refined, like a lovely small garden.

Cheng Xin and AA wandered over the barely inhabited continents of the Earth. They swept over endless forests, rode on trotting horses across grasslands, lingered over empty beaches. Most cities had become covered by forests and vines, leaving only small patches of civilization for the remaining residents. The total human population on the Earth was about what it was near the end of the Neolithic Age.

The longer they stayed on the Earth, the more all of civilization’s history seemed a dream.

They returned to Australia. Only Canberra remained inhabited, and a tiny town government there called itself the Australian Federal Government. The Parliament House where Sophon had proclaimed the plan for the extermination of the human race was still there, but thick layers of vegetation sealed its doors, and vines climbed up the eighty-meter-tall flagpole. They found Fraisse’s record in the government archives. He had lived until he was 150, but finally, time had defeated him. He had died more than ten years ago.

They went to Mosken Island. The lighthouse built by Jason was still there, but it was no longer lit. The region was completely uninhabited. They heard again the rumbling of the Moskstraumen, but all they could see was the empty sea in the light of the setting Sun.

Their future was equally empty.

AA said, “Why don’t we go to the world after the strike, the world after the Sun is gone? Only then will we find a life of serenity.”

Cheng Xin also wanted to go to that time, but not for a life of serenity. She had stopped a catastrophic war and she was becoming the target of the worship of millions. She could no longer live in this era. She wanted to see Earth civilization survive the dark forest strike and prosper after—it was the only hope that could comfort her heart. She imagined life in that post-strike nebula. There, she would find true tranquility, maybe even happiness. That would be the last harbor of her life’s voyage.

She was only thirty-three.

Cheng Xin and AA rode Halo back to the Jovian city cluster and once again entered hibernation in Asia I. The contracted-for time was two hundred years, but they included a provision in the contract stating they should be awakened if a dark forest strike occurred before then.

And then they slept. Dreamless.