Starfall

Starfall minus 2 months

Sol system

Minya had Curle brought before her.

Twenty-five years old, Curle was the last survivor of the Mutiny of the Grandchildren. The heads of the others were displayed frozen in the walls of Minya's cabin, here at the very heart of the comet nucleus. Minya had wanted to ensure there would be no recurrence of the Mutiny in the comet's final decade of flight.

She inspected Curle by the light of her fat candles. Held by two of her guards, he was gaunt, filthy, pale as a worm—well, everybody was, after two generations locked in the lightless heart of this comet. "You lost a leg," she said to him.

It took him some gulping efforts to speak. She didn't encourage speech in the cells. "Gangrene," he said.

"Ah. From a wound you incurred during the Mutiny, no doubt. Don't expect any sympathy from me. Anyhow we're in microgravity; you don't need legs. If you like I'll have the other one cut off for you. Balance you up." She made a scissoring gesture. "Snip, snip."

"Why have you brought me here?"

"I'll come to that. We're there, you see."

"Where?"

She showed him an image on an antique, low-power data desk, fed by a light pipe from the surface; the comet-ship designers hadn't even allowed the risk of radiation leakage from surface cameras. "Can you see? That's the sun—Sol. We've arrived in Sol system, after forty-nine years, right on schedule."

"And you're going to go through with it. Firing off the weapons."

"Of course I am. Wasn't that the whole point? You third-generation mutineers were such cowards."

He shook his head raggedly. "No. Lethe, it was ten years ago. I was only fifteen! If we'd been cowards we wouldn't have challenged you. This isn't our war, this war between the stars. How could it be? It's our grandparents' war. We live and die like worms in the dark. We wanted to let the Sol people alone, and just find a place to live—Sol system is a big place—" He laughed, or it may have been a cough. "I suppose it's big. I've never seen anything further than a couple of metres from my nose, so I wouldn't know."

She just smiled at him.

"And when you've shot the weapons off, what then? Do we wait for pickup by the Alpha ships?"

"Oh, I don't think that was ever very likely, do you? The Empress's soldiers would get to us long before then. No, I'm afraid that our little story was always bound to end here. And in that spirit I've done some redesign. The weapons systems were supposed to leave us with a habitable core, here in the nucleus. But what's the good of that? We're all dead anyway." She broadened her smile. "So I've weaponised everything—extended the potency of the damage we will cause. We will be remembered forever."

Curle lifted his head and looked at the faces of the guards who held him. They smiled, eyes gleaming; Minya was pleased by their determination, which showed the success of her conditioning of the surviving crew.

Curle asked, "That's your consolation, is it, you dried-up old witch? Comfort for your own death—for two wasted generations inside this block of ice—"

"Oh, off with you, back to your cell. I must say when I remember the high hopes we set off with, my poor husband Huul and myself, I think we would have regarded you as a grave disappointment."

"So why did you drag me out here?"

"To tell you how you were going to die. You did kill my babies, after all. Get rid of him."

August 11th, Starfall Day

Sol system

And then, without a subjective instant of delay, Max and the others found themselves falling into a new Store. It was a web of data spun between whole worlds, with mines of memory, troves of frozen order of an unimaginable size. And there was intelligence, artificial mind everywhere: a feast for a hungry, self-aware virus. This was not like the petty Stores where they had been raised; this went on forever!

Just for a moment the Eaters all hesitated, as if bewildered by the immensity of the feast set before them.

"He promised," Max said. "Flood promised! And he has delivered, hasn't he?"

He was answered by a roar from his jostling cohorts.

"For Flood! For Alpha! For the Starfall! Let us feed!"

And the Eaters plunged into the landscape of data before them, shitting out high-entropy disorder wherever they passed, feeding, multiplying, frenzied, unstoppable.

S-Day

London

The voice was booming, male, strangely accented to an Earth-bred ear.

"Take cover. The free citizens of Alpha system and the inhabited stars have no quarrel with the people of Sol system, but with your government. Flee the cities and the domed colonies. Take your children; take food, water, power and air. Find protection. Take cover. The free citizens of Alpha system—"

"Lethe, can't you shut that off?" Admiral Kale paced about the bunker under London, hastily buttoning up his uniform jacket, starburst at his chest.

Pella and the rest of Stillich's team sat in rows around a Virtual situation tank, hammering at data desks. "It's coming from outside the system," Pella said. "Probably all the way from Alpha. They might have used lasers—they have some mighty guns out there to push their lightsail ships—"

"I don't fucking care," said Kale. "Just jam it."

"That's impossible, sir," Stillich said bluntly.

"Take your children; take food, water, power and air. Find protection. Take—"

Abruptly the message cut off.

Stillich looked up. "Now what?"

"Captain," Pella said. "The situation display. Look."

The display was a rough cube, metres high, containing current and summary data on the empire's defences and the position of the Alpha invaders—the GUTship fleet was still a week away—complex, schematic, a constellation of data that changed by the second. But now whole blocks of the display were growing dark, as if shadows were falling.

Admiral Kale said, "Is this some fault? I thought you had back-ups—"

"Isolate your data desks from the central processing," Stillich said rapidly. "Do it now."

The staff hurried to comply.

Pella said, "Some of the drop-outs are at this end. But the transmitting stations are falling silent too. Port Sol—oh, wow, Mars just went. This is system-wide. Spreading at lightspeed, I think."

"Tell me what's doing this, Number One," Stillich said.

Pella's analysis was admirably fast. "Viruses," she said. "Semi-sentient. Voracious. They're just eating their way through our data stores, turning everything to mush. They seem to be targeting AI nodes particularly. It's a smart plague, and it's hitting us right across the system. They must have ridden in on the laser signal right after that warning—" Her data desk turned black. She sat back, disbelieving.

One man fell back from his station, clutching his chest. His colleagues rushed to help.

Stillich murmured, "Artificial heart. Anybody with implants of any sophistication is going to suffer."

Kale rammed a fist into his palm. "So they knock out our command and control before their ships even get here. And our people are no doubt already dying, as hospitals fail, and flitters fall out of the sky. Damn, damn."

"Captain, we're going to need to get to the surface," Pella said.

Stillich stood. "Yes. Take what you need. I hope the elevator is stupid enough not to have been infected, or it will be a long climb."

Kale growled, "Why the surface?"

"We have some systems up there that will still work. Those optical-fibre links we laid down are pretty dumb. We robustified the planet, remember? Although we didn't anticipate this."

"And what about the warning?" Kale asked. "Why issue that now? Their ships are a week out. You think that was referring to the viruses?"

Stillich frowned. "'Take cover ... Flee the cities and the domed colonies ... Take your children; take food, water, power and air'. Sounds like more than a virus to me."

"They're hitting us with something else, then. Other than the ships. Lethe. Listen, Stillich. Leave a skeleton crew down here. I want you to isolate that smart plague and fire it straight back at the rebels."

Pella said, "Maybe that's why they're sending manned ships. Proof against AI viruses. Surely they'll be shielded against their own weapons—"

"Then send them whatever else we've got too, with my best wishes."

Stillich hastily assigned some of his crew to carry this through. Then he hurried out after Pella and the Admiral.

They came up in the middle of Hyde Park. Under a clear August afternoon sky, they were military officers in gaudy uniforms, tense, sweating, armed, loaded with data desks and comms gear, emerging from a hatch in the green grass. Pella and the others immediately got to work setting up field comms stations.

Stillich looked around, trying to take stock. The bunker entrance was near the south-west corner of the Park, and through the trees he glimpsed the ruin of the Albert Memorial. The boundary of the Park wasn't clear, for parkland and oak forest covered much of London now; like most of Earth's cities it was like a garden from which buildings towered, needles so tall they penetrated a scattering of cloud. Above all that was the usual furniture of the sky, the contrails of descending spacecraft, the glittering sparks of offworld infrastructure.

But as Stillich watched one of those tremendous buildings quivered, and shattered glass sparkled from its face. Even the buildings needed smartness to stay up. And today the Park was crowded, and getting more full a" the time. People walked in carrying children, or bundles of belongings in cases, sheets and blankets. Some were trailed by serving bots, but many of these looked as if they were malfunctioning, confused.

There was a flash in the sky, like a high explosion. People ducked in unison, cowering from the sky. Moments later a distant sonic boom rumbled.

"It's that damn Alphan warning," said Admiral Kale. lilt's scared them all out of their homes. But this is a city of millions. Where are they supposed to go?"

Stillich said, "That warning was sent by planetary colonists. They live under domes, in towns of a few hundred, tops. I've seen them. The Empress was relying on their consciences to have them spare the cities. But what do they know of cities? Maybe they can imagine conditions on Mars or Titan. How can they imagine this?"

Kale said, "I wish there was something we could do for these people. Organise them. I feel helpless standing here."

"We'll have to leave that to the civilian police," Stillich said.

Now people were raising their faces to the sky. Stillich looked up.

The bright blue air was full of sparks that flared and died. And now there was another streak of light that cut across the sky, and a rippling boom of shocked air. Beyond that a broader explosion unfolded silently, like a flower.

"That," said Kale, "looked like a nuclear weapon."

"Sirs." Pella called them over. "We're getting some joy. The optic-fibre net is mostly intact, and some of our data desks stayed free of the viruses. The information flow is patchy. We've sent up another couple of recon satellites to replace those we've lost—"

"Damn it, woman, get to the point. What's happening to us?"

"It's the comet, sir. You were right, Captain."

The stray comet, buried deep in the heart of Sol system, had burst, transforming in a flash into a shoal of kinetic-energy weapons—dumb but massive, fast-moving, and precisely targeted.

"They've been hitting us off-world," said Pella. "Obviously we're vulnerable wherever there's no decent atmospheric cover. Mars, the big dome over Cydonia. They targeted the Serenitatis accelerator on the Moon, for some reason. There is what appears to be a shoal of the things heading out to Titan, Port Sol—we may be able to intercept some of them—the smart plague isn't helping us deal with this, of course."

"A crude tactic, but effective," the Admiral said. "And Earth?"

The comet bombs had first targeted the off-planet infrastructure. The planet's space-elevator beanstalks had all been snipped, and orbital power nodes, resource lodes and comms satellites were being smashed. Earthport, the wormhole Interface cluster, had been particularly heavily targeted. In with the dumb bombs there was a scattering of high-yield nuclear devices, emitting electromagnetic pulses to disable anything too small to be targeted individually.

A second wave of the comet-ice bombs was raining down into the atmosphere, targeting power facilities like dams and the big orbital-power microwave receiver stations, transport nodes like harbours, air—, space— and seaports, bridges, road and rail junctions, traffic control stations.

"There haven't been too many casualties yet," Pella said. "Anyhow we don't think so. Some collateral stuff—where dams have come down, for instance. And the smart plague has hit monorails and flitters and orbital shuttles; you have stuff just falling out of the sky, crashes everywhere."

"They're disabling us rather than killing us," Stillich said.

"Looks that way," growled the Admiral. "So they got in through stealth. I should have listened to you about that damn comet, Captain. You must be sick of being told you were right."

Stillich shook his head. "It's not important, Admiral. What scares me is what else we have missed. That's been the trouble through this whole exercise. None of us can imagine—"

Pella held her hand up, her hand at her ear. "Wait. There's another of their messages coming through." She touched her data desk. The same booming male voice, with its flat Alphan accent, sounded out. " ... free citizens of Alpha system and the inhabited stars have no quarrel with the people of Sol system, but with your government. We mean this final strike to be a demonstration of our capability. Please take all precautions necessary, especially along the North Atlantic seaboard. The free citizens of Alpha system ... "

Pella looked at Stillich nervously. "What 'final strike'?"

There was a burst of light in the west, like a sudden dawn. Again everybody flinched. The light seemed to draw down the sky, too bright for Stillich to look at directly.

"Call a flitter," he snapped at Pella.

'Sir—"

“Do it! Get us out of here. And find a way to get a warning to the Empress in New York."

S-Day plus 3

Sol system

They hung a huge Virtual globe of the Earth in the lifedome of the Freestar, Flood's flagship. The crew watched the disaster unfold, mouths slack in awe.

The Atlantic impactor had been the biggest single chunk of the comet, but it had been as precisely targeted as the rest. It had come down in the middle of the ocean, on a ridge of continental-crust formation about a thousand kilometres south of a small island called Iceland.

From viewpoints on the ground, a particle of light was seen to descend from the sky, touching the water, and then, behind a wall of boiling cloud, a pencil of light shot vertically to the sky.

From space, as rings of cloud expanded, a fireball blossomed, clinging to the carcass of the planet like a boil. The cloud rings merged to become a solid torus, centred on the fireball, and then more clouds formed at higher level. A shock wave spread out through the cloud layer, a reflection of a ring of waves spreading out across the ocean, a water ripple dragging a wall of cloud with it.

The ripple in the ocean emerged into clear air. It was barely visible by the time it approached the land, at Newfoundland to the west and Ireland to the east. But it mounted quickly as it hit the shallowing bottoms of the continental shelves, water forced up into a heap, a wave with the volume and vigour to smash its way onto the land. All around the basin of the North Atlantic the steel-grey of the ocean overwhelmed the greenish grey of the land, the complexities of coastal topography shaping the water's thrusts. As the Alphans watched, the continents changed shape.

Beya was Flood's eldest daughter. At twenty-five years old she had become one of his most capable officers. She watched the repeated diorama in shock. "I heard garbled reports. In some of those lands around the rim of the ocean, before the wave came, they said there was salt in the rain. You know, when I heard that, I didn't know what 'rain' was, exactly. J had to look it up." She laughed. "Isn't that strange?"

"This is a demonstration," Flood said grimly. "The people of Earth know that far larger impactors have battered the planet in the past, causing vast pulses of death, even extinction. This will show them that we want victory, not destruction—but we hold destruction in our hands. This will work on their imaginations."

"Well, it's working on mine," Beya said. "Dad, I never saw an ocean before. A moon-full of liquid water, just sitting there without a dome! Earth is alive, you can see it, not some lump of rock. And now we've hurt it."

"We were never going to be able to loosen the eight-hundred-year grip of the Shiras without being strong."

"But they will never forgive us for this," Beya said.

"It's necessary, believe me." He reached for her shoulder, then thought better of it. "Any news of the Second Wave, the comet crew?"

"Nothing was left of the comet, it seems."

"Maybe the imperial military got to it. That's one ship I'm glad I wasn't on, I must say." He glanced over, to see the Virtual Earth running through its cycle of trauma once again. "Shut that thing down," he called. "Look, we broke through their outer perimeter without a single loss. In twelve hours we make perihelion, closest approach to the sun. We've all got work to do. Tomorrow, it's Sol himself!"

S-Day plus 4

Solar orbit

The Thoth habitat was a compact sculpture of electric blue threads, a wormhole Interface surrounded by firefly lights. The surface of the sun, barely twenty thousand kilometres below the habitat, was a floor across the universe. Thoth was over nine hundred years old. And all his long life it had been home to Sunchild Folyon, leader of the little community which maintained Thoth, a legacy from the past, held in trust for the future.

But now the rebel fleet was approaching its perihelion, its closest approach to the sun—and Thoth's most significant hour since its construction by Michael Poole was almost upon it.

After prayers that morning Folyon went straight to the habitat's bridge, where, even through the prayer hours, shifts of sunchildren maintained watch over Thoth's systems and position. The mood on the bridge was tense, for the wormhole into the heart of the sun had been shut down for twenty-four hours already, a time unprecedented in Folyon's memory; maintenance downtimes were usually measured in minutes.

But this was an extraordinary moment which required extraordinary measures, as the Empress Shira had patiently explained to Folyon himself—and as he himself had had to relay to a reluctant Lieserl, deep in the belly of the sun. This was total war. Even Thoth had been infected by the smart plague. Every resource available to the empire had to be dedicated to the fight—and that included even Thoth and its ancient community. So Thoth's orbit had been carefully lifted from equatorial to a higher-inclination plane where the habitat was expected to lie in the path of the invasion fleet; and so the wormhole had, for now, been shut down.

The sunchildren had fulfilled their duties to the letter. But Folyon, conditioned since childhood to dedicate his life to a single goal, had found it hard to accept this distortion of his deepest imperatives.

Not wishing to exacerbate the crew's difficulty with his own qualms, he left the bridge and made for the observation deck. As so often, he dealt with his troubles by immersing them in the healing light of the sun, giver of life.

The sun was a flat, semi-infinite landscape, encrusted by granules each large enough to swallow the Earth, and with the chromosphere—the thousand-kilometre-thick outer atmosphere—a thin haze above it all. The sunscape crawled beneath the habitat slowly, but that slowness was an artefact of scale, a collision of human senses with the sheer bulk of the sun. In this free orbit around the sun Thoth was actually travelling at five hundred kilometres a second. Folyon knew how privileged he was to spend his life in the orbit of the mighty star, the physical and philosophical core of human culture. At the prayer hours he would look away from the sun's processed light to the distant stars, and he imagined every human eye, even across interstellar distances, turned to the sun, towards him.

And he wondered how many of those observers even knew of the habitat's existence, or its purpose.

Deep below the habitat, tracking its orbit, the tetrahedral Interface of a wormhole, linked to the mouth tended by Thoth, was suspended in the body of the sun. Searing-hot gas poured into its four triangular faces, so that the Interface was surrounded by a sculpture of inflowing gas, a flower carved dynamically from the sun's flesh. In normal times this solar material would spew from the wormhole mouth cradled by Thoth, to dissipate harmlessly. Thus the wormhole was nothing less than a crude refrigeration mechanism, by which solar heat was pumped away from the fragile human-built construct that housed the soul of Lieserl, and enabled her to survive in the sun's fire. And it was all for a higher goal. Lieserl was a monitor, sent into the sun to investigate a complex, dark-matter canker that seemed to be building up at the star's heart.

Thoth's purpose outdated even the ancient empire of the Shiras, but, designated as a temple to Sol, it had always been maintained faithfully by the Empresses' lieutenants. Now Lieserl's wormhole was to be used as a weapon of war—but even this remarkable incident, Folyon knew, was but an episode in the greater history of Thoth and Lieserl.

A sunchild touched his arm, a young woman. His thoughts, as so often, had drifted away from the here and now. Sunchild Mura said, "The time is close, sun-brother."

"All goes well on the bridge?" He felt anxious.

Mura was empathetic for a girl of her age and she knew his moods. "Everything is fine. You would only distract them all, forgive me for saying so, sun-brother."

He sighed. "And so we go to war."

"They tell me you can see it from here. The fleet." She scanned around the sky—every photon passed by the observation deck blister was heavily processed—and pointed to a cluster of starlike points, far away above the sunscape. "There they are."

The lights grew in size and spread apart a little; Folyon saw now that they were splinters, like matchsticks, each with blazing fire at one end. "An enemy fleet from Alpha Centauri, come all the way to the sun. How remarkable."

Mura counted. "Five, six, seven, eight—all accounted for. And their GUT drives are firing./I This was celestial mechanics, Folyon knew; if you entered the solar system from outside perihelion was energetically the most advantageous place to dump excess velocity. "They will come close; the projections of their trajectories are good," Mura said, sounding tense. "And they will come on us quickly. The moment of closest approach will be brief. But the systems are automated—the reopening of the wormhole won't rely on human responses." She hesitated. "Did you tell Lieserl what is happening today?"

"I thought it was my duty," he murmured. "She will remember all this, after all, long after the rest of us are dust. I wonder if they are praying."

"Who?" Mura asked.

"The crews of those ships. For they worship Sol too, do they not? And now we are about to use Sol itself to kill them." He lifted his face, and his old skin felt fragile in the sun's processed light. "Do we have the right to do this? Does even Shira?"

She grabbed his arm. "Too late now—"

The ships exploded out of the distance. And at closest approach solar gases hosed from the drifting wormhole Interface, turning it into a second, miniature sun. Solar fire swept over the invaders. Mura whooped and punched the air. Folyon was shocked and troubled.

S-Day plus 4

Oort Cloud, outer Sol system

Densel Bel wished he could see the sun, with his naked eye. After all, he was among the comets now, within the sun's domain.

He stood in the dark, peering up at the zenith, the way the ship was flying; he tried to imagine he was rising in some spindly, superfast elevator. A light-week out from Sol, with the ship travelling at less than two per cent below lightspeed, the view from the lightdome of the Fist Two was extraordinary. All was darkness around the rim of the hemispherical lifedome. The only starlight came from a circular patch of light directly over his head, crowded with brilliant stars, all of them apparently as bright as Venus or Sirius seen from Earth. He knew the science well enough; the starfield he saw was an artefact of the ship's huge velocity, which funnelled all the light from across the sky into a cone that poured down over his head, even from stars directly behind the ship as it flew.

And meanwhile the stars he was able to see were not the few thousand visible in solar space by the naked human eye. His extraordinary speed had imposed a Doppler effect; the stars behind had been redshifted to darkness, while the 'visible' stars ahead, including the sun, had similarly been blueshifted to obscurity. But conversely red stars, giants and dwarfs pregnant with infra-red, now glowed brightly, crowding the sky, a hundred thousand of them, it was thought, crammed into that tight disc.

Sol itself was somewhere in there, at the dead centre of his visual field, and he knew that the navigators on the bridge had elaborate routines to disentangle the relativistic effects from the starfield. But a primitive part of him longed just to see the sunlight again, with his own unaided eyes, for the first time in so many decades—

Snow sparkled over the lifedome, gone in an instant. He flinched, half-expecting the blister to crack and crumple over him. He called, "What was that?"

A Virtual of Flood appeared in the air before him, the avatar // used by the ship's AI to communicate with the crew. "We lost Fist One," Flood said bluntly.

"How?"

"A dust grain got it. The earthworms. They blew up an ice asteroid in our path, creating a screen of dust hundreds of kilometres wide. We have defences, of course, but not against motes that size, and at such densities. At our velocity even a sand grain will hit with the kinetic energy of a—"

"There shouldn't be any asteroids here. We're out of the plane of the ecliptic."

"Evidently the earthworms have prepared defences."

"So how come we survived?"

"The destruction of One blew a hole in the debris cloud. We sailed through."

Densel considered. "So if we follow each other, even if the lead ship is taken out by further screens, it might clear a path for the rest."

"That's right. We will still achieve our objective if only three, two, even just one of the Fists gets through." Flood hesitated, and the image crumbled slightly, a sign of additional processing power being applied. "There is other news. The Third Wave ships came under fire when they rounded the sun. Two were lost."

"That was smart by the earthworms." Densel wondered if he ought to be exulting at this victory, for Earth, after all, was his home planet. But his heart was on Footprint, with the families he would never see again. He didn't want anybody to die, he realised.

Flood said, "Smart, yes. But six ships survive, of eight. Meanwhile the earthworms are regrouping. Half of their ships, twelve of them, are heading for Jupiter." Flood nodded. "We have to eliminate the Navy, to win. Then that is where the decisive encounter will come, for the Third Wave."

"And the other earthworm ships?"

"Converging on the course of the Fists."

Densel nodded. "But now, in Two, I'm in the van. The next in line for the duck shoot."

Again that hesitation, that fragility. "The crews are conferring. That would not be optimal."

"Optimal?"

"The line is to be reconfigured. Fist Two will continue astern of the remaining ships, not in the lead, protected by the others."

"You want to give Two the best chance. Why?"

"Because Two has you aboard." The avatar grinned, an imperfectly imaged, eerie sight. "I told you. You are useful, Densel Bel." Theatrically it consulted a wristwatch. "Subjectively you are little more than a day away from Sol. Thirty-three hours, that's all it will be for you. Then it will be done. Try to get some sleep." It crumbled to pixels and disappeared.

S-Day plus 6

Imperial bunker. New York

Admiral Kale was shocked by what he found of New York.

The great wave had spared some of the mighty old buildings, which stood like menhirs, windows shattered, their flanks stained by salt water. But the human city at their feet was devastated, scoured out, millennia of history washed away. Even now the aid workers and their bots dug into the reefs of rubble the wave had left, and the refugees were only beginning to filter back to what remained of their homes.

But in her bunker of Construction Material, deep beneath the ruin of Central Park, the Empress sat beside her pool of logic and light, imperturbable.

"You are angry, Admiral Kale," she said softly.

"Every damn place I go on the planet I'm angry," he said. "The destruction of history—the harm done to so many people."

"We are not yet defeated?"

The tone of the question surprised him. "No, ma'am, we are not. We are massing the Navy cruisers at Jupiter—"

"I have viewed the briefings," she said.

"Ma'am." He stood and waited.

"I have brought you here, Admiral, to speak not of the present but of the past, and of the future. You spoke of history. What do you know of history, though? What do you know of the origin of the empire you serve—and, deeper than that, the dynasty of the Shiras?"

He was puzzled and impatient. Surely he had better things to do than listen to this. But she was the Empress, and he had no choice but to stand and take it. "Ma'am? I'm a soldier, not a scholar."

"I need you to understand, you see," she rasped. "I need someone to bear the truth into the future. For I fear I may not survive this war—at least I may not retain my throne. And a determination that has spanned centuries will be lost."

"Ma'am, we're confident that—"

"Tell me what you know."

Hesitantly, dredging at his memory, he spoke of the Emergency nine hundred years before.

The great engineer Michael Poole had opened up Sol system with his wormhole projects, and worked on the first generations of interstellar craft. But Poole had greater ambitions in mind. He used wormhole technology to establish a time tunnel: a bridge across fifteen hundred years, a great experiment, a way to explore the future. But Poole's bridge reached an unexpected shore. The incident that followed the opening of the wormhole was confused, chaotic, difficult to disentangle. It was a war—brief, spectacular, like no battle fought in Sol system before. It was an invasion from a remote future, an age when Sol system would be occupied by an alien power.

The incursion was repelled. Michael Poole drove a captured warship into the wormhole, to seal it against further invasion. In the process, Poole himself was lost in time.

"An invasion from a dark future, yes," hissed the Empress. "An invasion from which the first Shira, founder of the dynasty, herself was a refugee. She saw Poole disappear into time, collapsing the wormhole links. And when the way home was lost, Shira was stranded. But she did not abandon the Project."

"The Project?"

"Shira belonged to a philosophico-religious sect called the Friends of Wigner. And their purpose in coming back in time was to send a message to a further future yet ... "

Kale, frustrated, had to endure more of this peculiar philosophising.

Life, Shira said, was essential for the very existence of the universe. Consciousness was like an immense, self-directed eye, a recursive design developed by the universe to invoke its own being—for without conscious observation there could be no actualisation of quantum potential to reality. And if this were true, the goal of consciousness, of life, said Shira, must be to gather and organise data—all data, everywhere—to observe and actualise all events. In the furthest future the confluences of mind would merge, culminating in a final state: at the last boundary to the universe, at timelike infinity.

"And at timelike infinity resides the Ultimate Observer," Shira said quietly. "And the last Observation will be made." She bowed her head in an odd, almost prayerful attitude of respect. "It is impossible for us to believe that the Ultimate Observer will simply be a passive eye. A camera, for all of history. We—the Friends of Wigner, the sect to which Shira belonged—believe that the Observer will have the power to study all the nearly-infinite potential histories of the universe, stored in regressing chains of quantum functions. And that the Observer will select, actualise a history which maximises the potential of being. Which makes the cosmos through all of time into a shining place, a garden free of waste, pain and death."

She lifted her head abruptly, and the light from the logic pool struck shadows in her face. She was quite insane, Kale thought.

"It is essential that humanity is preserved in the optimal reality. What higher purpose can there be? Everything the Friends did was dedicated to the goal of communicating the plight of mankind to the Ultimate Observer. Even the destruction of Jupiter. And even I, stranded here in this dismal past, stranded out of time, have always struggled to do what I could to progress the mighty project." She peered into the logic pool. "I, in my way, am searching . .. "

He stared at her. "Ma'am—you said 'we'. You speak of yourself as a Friend of Wigner. Not the first Shira."

She lifted her face, its skin papery.

"You are Shira. The first. There was no dynasty, no thirty-two Shiras, mother and daughter—just you, the first, living on and on. My, you must be nine hundred years old."

She smiled. "And yet I will not be born for another four hundred years. Am I old, or young, Admiral? Once the Poole wormhole was closed down I had lost my route back to the future. I accepted that. But there was always another way back. The long way. I accepted AntiSenescence treatment. I began to accrue power, where I could. And then—"

"And then," said Kale, barely believing, "it was a simple matter of living through fifteen centuries—fifty generations—and waiting for your time to come again."

"You have it, Admiral."

He peered at her. "Were there others like you—others stranded in history?"

"None that remain in Sol system." Her face was blank. "None that survive."

"You monopolised knowledge of the future to cement your power base." He remembered himself. "Ma'am, forgive me for speaking this way—"

"It's all right, Admiral. Yes, you could put it like that. But it was necessary. After all there had been no unified government of mankind, none before me. Quite an achievement, don't you think? Why, I had to invent a religion to do it ... It was necessary, all of it. I need the shelter of power. There are many obstacles to be overcome in the decades ahead, if I am to survive to the year of my birth."

"Ma'am—I thought I knew you."

"None of you knows me, none of you drones." She withdrew. "I tire now. Progress your war, Admiral. But we will speak again. Even if I fall, the Project must not fail. And I will entrust in you that purpose."

He bowed to her. "Ma'am." And with huge relief he left the chamber, leaving the lonely woman and the light of the logic pool behind him.

S-Day plus 9

Jupiter

The earthworm fleet was assembling here too, somewhere on the far side of the giant world. The showdown was still hours away, the Alphan planners believed.

Despite the urgency of the situation, despite all Flood's urging and imprecations, every chance they got the crew of the Freestar stared out of their lifedome at Jupiter. After all there were no Jovians in Alpha system.

It was a bloated monster of a world, streaked with autumn brown and salmon pink. And, still more extraordinary, it was visibly wounded, immense storms like funnels digging deep into its surface. The other ships of the rebel fleet, the other five of their minuscule armada, drifted across the face of the giant world, angular silhouettes.

One other structure was visible in its own orbit, deep within the circle of the innermost moon, Io. It was an electric-blue spark, revealed under magnification to be a tangle of struts and tetrahedral frames. This was the Poole hub, where Michael Poole had used the energies of a flux tube connecting Jupiter to Io to construct the heart of his intrasystem wormhole network. Even today one of those ancient Interfaces linked Jupiter itself to Earth—or it had until the earthworms had cut it.

It was an extraordinary sight, Flood conceded. "Spectacle and history, all mixed up."

"Yes, dad," said Beya. "You know I've been reading up on Sol system history ... "

He did and he didn't entirely approve; it struck him as a guilty reflex.

"You say this is all because of human action?"

"That's the story," he said. "Though my grasp of ancient earthworm history is shaky."

Nine hundred years before, Jupiter had been wrecked by the actions of the Friends of Wigner, rebels from a dismal, alien-occupied future. The Friends had had in mind some grand, impossible scheme to alter history. Their plan had involved firing asteroid-mass black holes into Jupiter.

"Whatever these 'Friends' intended, it didn't work," Flood said. "All they succeeded in doing was wrecking Jupiter." He shook his head. "The greatest mass in Sol system after the sun itself, a vast resource for the future—ruined in a single action. How typical of earthworm arrogance!—"

Light sparked in the complex sky. Flood saw it reflected in his daughter's face. He turned.

One of the rebel ships, the Destiny of Humankind, had exploded. The delicate spine was broken, the detached GUTdrive flaring pointlessly, and the fragile lifedome shattered, spilling particles of pink and green into space.

Alarms howled. Virtual control desks appeared before Beya and Flood, crammed with data. The crew, sleepy, shocked, scrambled to get to their positions.

And then another ship detonated. The Future Hope, a ship five hundred years old, gone in a second. This time Flood glimpsed the missile that took it out. But there was no time to reflect.

"Incoming," Beya called. "Incoming!"

Flood worked at his desk with brisk sweeps of his fingers. "All right. We're evading." The lifedome shuddered as the GUTdrive flared, shoving the Freestar sideways.

A missile streaked past the lifedome, close enough to see with the naked eye, glowing white-hot.

"Shit," Beya said. "How are they doing this? The scans showed a volume around us was clear."

"Jupiter," Flood said, reading his displays rapidly. "The missiles are coming out of Jupiter. But the velocities are so high—I don't understand."

"The black holes," Beya said. "Maybe that's it. They're slingshotting their missiles off the central black holes. You can pick up a hell of a lot of kinetic energy from an ergosphere."

"And they're punching out of the carcass of the planet, right at us. Incredible."

Another ship flared and died, a flower of light pointlessly beautiful.

"The Dream of Alpha," Flood read. "That's three of us gone in a few seconds. They're picking us off. Three of us left, against a dozen Navy cruisers. We'll have to withdraw. Regroup if we can—"

"No." Beya was working hard at her desk. "Dad, there's no time for that. Tell the survivors to make for the Poole hub."

"Why? The wormhole links are severed; we can't get away from there."

"It will give us a bit of cover. And I've an idea," she said, distant, working.

Flood frowned. He didn't enjoy it when this determined side of his daughter showed itself; it made her seem too strong, too independent—he couldn't protect her any more. But she had called the black-hole missile manoeuvre correctly. He saw no better option than to accept her recommendation. He snapped out the orders.

The Freestar's GUTdrive kicked in. The acceleration mounted quickly, two, three, four gravities. Flood felt it in his bones, but he stood his ground, determined. Above his head, Jupiter slid with ponderous slowness across his field of view. "Come on," he said. "Come on ... "

Elsewhere, aboard the bridge of the Navy ship Facula, there was much cheering at the downing of half the rebel fleet—premature cheering, as far as Stillich was concerned.

"Status," he yelled at Pella, above the noise.

"Three down, three to go."

"But the three survivors aren't running."

"Not from Jovian space, no sir. They seem to be making for the Poole hub."

"Why there?"

Pella tapped a desk. "The war-game AIs have no idea. If they need cover they could run to one of the moons ... " She grinned. "Sir, who cares? We have twelve ships against three. We can shoot them out of the sky."

Stillich felt deeply uneasy, but he couldn't argue with that analysis. "Well, that's the idea, Number One. All right. Call the fleet; set up an attacking perimeter."

"Sir."

The GUTdrive surged smoothly.

Twelve ships against three. The decision to withdraw the Sol fleet to Jupiter had been a good one, Stillich thought. The hinterland of the giant planet was a dangerous, complex place, laced with strong gravitational fields, intense radiation and hazards like the Io flux tube. It was a battleground much more familiar to the defending Navy than to the attackers—and he had been impressed by the innovative thinking at a Navy college on Earth that had come up with the notion of using the black hole slingshot to pick off the rebels even before the ships had engaged.

But once he had accepted the stratagem, Stillich had argued for withdrawing all of Earth's fleet to Jupiter or its environs, not to leave half of it mounting a futile picket fence at the incoming relativistic wave. Twelve against three. It was more reassuring than twelve against six had been, but Stillich was in no mood for anything less than a complete victory, an annihilation, the security of the system demanded it, and the more overwhelming the odds the better.

On the Freestar, the Poole hub was already approaching, a cluster of Interface portals hurtling over the horizon towards the surviving rebel ships, a tangle of electric blue.

"Lethe," Beya breathed. "I didn't know how beautiful it was."

Flood said softly, "The wormholes are gateways to other times, other places. They should be beautiful, like all great engineering."

Alarms chimed once more.

Beya studied her data desk. "They're closing in, dad, a dozen Navy cruisers."

"Then this is it." He clenched his fists. "Let's at least back up against the wormhole hub. Have the AIs war-game an optimal configuration—"

Beya kissed him on the cheek, a lingering gesture that still felt too brief. "Cover me."

"What?"

She turned and ran, faster than he could hope to catch her. "I told you I have an idea." And she ducked out of sight, through a hatch to the ship's spine.

A missile soared past the lifedome, and the crew ducked, involuntarily. Then there was a speckle of laser light, and the dome blister blacked itself out. Grey Morus, Flood's second in command, yelled across, "They've got our range, Flood. We're shooting back but—"

Flood's data desk chimed. The AIs had come up with a defensive configuration for the ships, lifedomes together, tails out, backed up against the Poole hub, using superhot GUTdrive exhaust for defence. "Copy this and implement," he snapped at Grey. He punched his data desk. "Beya! Where are you?"

In Beya's flitter, her father's voice was as clear as if he was riding alongside her. Beya was determined to keep her voice level. "Can't you see me, dad? I'm up around your ten o'clock—oh, but your blister is blacked out."

"What the hell are you doing up there?"

The flitter ducked sideways, jolting her against her restraints. "I'm taking fire, that's what I'm doing. Dad, if you've got a spare laser, cover me!"

Now the flitter swept around. She was heading straight for the Poole hub, a tangle of wormhole mouths, powder blue. She saw the three ships of the invasion fleet backing up, pirouetting clumsily into their defensive position. But the Navy ships swept across her view, soulless, mechanical, spitting missiles at the rebels, bathing them with laser light. There were so many of them, a dozen against three.

And as she watched a Navy missile got through, hammering into the GUTdrive pod of the Mercy and Tolerance. Slowly the great ship began to drift out of position. But even as she did so she spat fire in Beya's direction, and picked a Navy missile out of the sky.

"Thanks, Mercy/' she whispered.

"You're welcome/' came a reply.

"Beya, what are you doing?"

"Dad, do you trust me?"

"I—You know I do. What kind of question is that?"

"Well enough to gamble your life on my say-so?"

"I may not have a choice. If you'd just tell me—"

"Just another bit of Sol system history, dad. Something I read, an incident at a planet called Pluto, long ago ... " She stared out at the dazzling sky-blue of the nearest portal's exotic-matter tetrahedral frame. The faces were like semitransparent panes of silvered glass; she could make out the watercolour oceans of Jupiter, swirled around in a fashion the eye could not quite track, like visions in a dream. "So beautiful."

"Beya?"

The flitter turned its nose straight towards the Interface. She ran a quick calculation on her data desk.

"Five seconds, dad."

"Until what?"

"Fire up on my mark, and get out of there with everything you have."

She passed through the glimmering face as if it did not exist, and now she was inside the blue frame of the Interface.

Her father's voice was distorted. "Beya, please—"

"This is for you, for mum, for Alpha. Remember me. Mark!" And she stabbed down her finger at her data desk.

The flitter's engine exploded. Something slammed into her back. Electric-blue light flared all around her.

Remarkably, she was still alive.

She was jammed up in the little ship's cabin, which had been ejected from the wreck. She made herself look around. She gasped with the pain of broken bones.

There was something wrong with space. A ball of light, unearthly, swelled up behind her, and an irregular patch of darkness ahead was like a rip in space. Tidal forces plucked at her belly and limbs. Nobody had had a ride like this in a thousand years.

And she saw Navy ships scattered like bits of straw in a wind.

The tides faded. The darkness before her healed, to reveal the brilliance of Sol. And the flitter cabin imploded, without fuss.

It took long minutes before the crew got the tumbling of the Facula under control.

Pella came to Stillich, her brow bloodied. "Damage report—"

"Never mind that. What just happened?"

"An Alcubierre wave."

"A what?"

Pella dragged her fingers trough mussed hair. "Captain, a wormhole is a flaw in space. It's inherently unstable. The throat and mouths are kept open by active feedback loops involving threads of exotic matter. That's matter with a negative energy density, a sort of antigravity which—"

"What's an Alcubierre wave?"

"Something exploded inside the Interface. And the Interface's negative energy region expanded from the tetrahedron, just for a moment. The negative energy distorted a chunk of spacetime. The chunk containing us."

On one side of the wave, spacetime had contracted like a black hole. On the other side, it expanded—like a re-run of the Big Bang, the expansion at the beginning of the universe.

Pella scanned her data desk. "We lost contact altogether with five of our ships. None of the ships is operational. The Facula—"

"What about the surviving rebels?"

"Two disabled." She looked up. "One got away. It's heading for Earth."

"Can we give chase?"

"No, sir, we—"

"Get me a line to Admiral Kale. Patch it through to the Palace if you can—"

She looked up again, shocked. "Sir. I've a standing order, to become operative in case of failure."

"Get on with it."

"You're relieved of command. In fact, you're under arrest."

Stillich laughed. "Fine. I'm in your custody, Number One. Now get hold of a working flitter and get me back to Earth."

S-Day plus 11

Orbit of Neptune

The final attempt to stop the Fist ships was the most dramatic.

After ice-moon debris had put an end to One and then Four, it was a GUTship that tried to halt the last two survivors, Three and Two. Not far within the orbit of Pluto, on the rim of Sol system proper, moving at a fraction of the attackers' near-lightspeed, it tried to ram them. It was an extraordinary bit of relativistic navigation. Fist Three, taking the lead, destroyed it with an equally remarkable bit of sharp-shooting. But the detonation hurled debris into the path of Three, and that was that.

When it was done, here was Fist Two alone, sailing on through the orbit of Neptune at over ninety-eight per cent of lightspeed—the fastest velocity ever attained within the system, it was believed, save for cosmic rays, atomic nuclei ejected from supernovas.

Fist was a warship, a relativistic weapon, manned, sailing among the fragile worlds of the mother system. It was wrong, Densel Bel thought. It was monstrous. And yet here he was. Densel Bel was glad the remaining time was so brief.

S-Day plus 11

Imperial bunker, New York City

Stillich was brought to the Empress's bunker in shackles.

Admiral Kale was here. With an impatient command he ordered the shackles removed, and dismissed the guard.

Beside the logic pool, in its eerie, shifting light, the Empress brooded. Some Virtual display was playing itself out before her: a globe, a point of light, a glowing splinter—over and over.

Stillich approached his superior, rubbing his ankles. "Sir. How long?"

Kale snapped his fingers; a small Virtual data display appeared in the air. "That fucking relativistic ship is crossing Saturn's orbit."

Stillich thought. "Seventy-eight minutes from Earth."

"About that. And we're still waiting on this bastard Flood."

After the Navy's scattering at Jupiter, there had been nothing left to stand in the way of the Freestar's advance on Earth. At last the rebel ship had entered orbit around Earth itself, and Flood was descending to discuss surrender terms.

"Do you think we've a choice but to do what he says?"

Kale grimaced. "The choice is playing itself out on the Empress's lap."

The consequence of the Fist striking the Earth had been modelled for the Empress. The physics was simple, a function of the fist's immense kinetic energy. The impact, marked by a tunnel of air shocked to superheated plasma, would be the source of a pulse of electromagnetic energy itself strong enough to sear anything alive across half a hemisphere—bright enough to pierce walls. The shock waves of air and water that would follow, and a hard rain of melted bedrock falling from the sky, would do the rest. Shira watched this over and over, obsessive.

At the seventy-minute mark, the chamber door opened. Flood walked in. He was a bulky, strong-looking man, wearing a simple tunic and leggings. He carried a package, a sleek black box. Two others accompanied him, a man and a woman similarly dressed. These companions looked nervous, even over-awed, to be in this bunker under New York City itself, to be in the presence of an Empress. Flood, however, showed no fear.

Flood glanced at the Empress. She showed no reaction, watching her model go through its sequence, over and over.

Kale sneered. "So you are Flood, the great rebel leader. And you dress like a farmer. How ostentatious. How predictable."

Flood smiled at him, and looked him up and down. "Nice jacket. Here. Hold this." He handed him the box he was carrying.

Kale took it reflexively. Then, irritated, he passed it to Stillich. "What is it?"

"Our final weapon. A nanotech modification of the smart plague—hardware, not software. Released, it would chew up the robust networks you were prudent enough to install—your optical-fibre links and all the rest. Necessarily delivered after landfall."

Stillich put this on the floor, gingerly. "Your final weapon save for the fist."

"Save for that, yes."

"Why have you brought it here?" the Admiral asked. "You have won. You have no need to do more damage."

Flood walked to the rim of the logic pool. "To put an end to that."

Now the Empress spoke. "You are Flood."

He bowed. "Empress—"

"Shira will do."

"Yes. Shira is your name. It always was, wasn't it? I am here to discuss terms."

Stillich said tensely, "Keep it brief, farmer. We don't have much time."

"Brief I can manage. Your Empress must stand down. This logic pool must be shut down—here, now, immediately, before my eyes. And we begin the establishment of a constitutional convention. A new relationship between the free worlds of all mankind."

"How civilised," Kale said. "A constitutional convention, or global obliteration."

"Admiral," Stillich snapped. "We don't have the time. Flood—why the logic pool? This is at the centre of everything, isn't it?"

Flood faced Shira. "The centre of all she is doing. Isn't that true, ma'am?"

"How little you understand," Shira said.

"Oh, I think I understand well enough." Flood faced the Navy men. "You know her story by now. She is a refugee from the future—from a time that, even nine hundred years later, is so far remote it remains the future. And she is going home the long way, year by year, heartbeat by heartbeat. But it isn't the future she longs for - is it, Shira? You don't want to be in this universe at all ... "

Kale had tried to explain Shira's extraordinary ideas to Stillich, and Stillich thought he understood. "Ma'am? Is he right?"

"None of this is real," Shira said, her voice a husk. "It is all transitory. We are simply forced to endure the motion of our consciousness along one of the chains of quantum functions, a sequence of potentiality to be collapsed, discarded, by the Ultimate Observer at timelike infinity ... "

Stillich tried to control his impatience. "This is just anachronistic philosophy. I don't see what it is that she's doing here that disturbs you, Flood."

"She longs for her Ultimate Observer. And she thought she could find her quantum messiah in mathematics ... "

The logic pool, he said, was a meta mathematical universe. While not infinite it comprised more mathematical understanding, far more, than had yet been explored by mankind—and in principle, somewhere within the meta mathematical branching of the pool, any algorithm possible might exist.

Shira said softly, "All our science is based on the search for simple rules underlying complex phenomena. Simple algorithms can be shown to generate complexities, from the turbulent flow in a glass of water to the spiral structure of the Galaxy itself."

"You see the idea," Flood said. "There's a lot of nonsense in there, but also a lot of treasure to be dug out. It's as if you have a tank full of every possible combination of words in Earthish. Most of it is dross. But in there to be discovered are the finest works of human literature—even those not written yet."

"And similarly, I suppose," Stillich said, "scientific understanding not yet acquired."

"Well, yes. But Shira has always been more ambitious than that, haven't you, Empress?"

Shira said, "Human consciousness is likewise the product of simple algorithms with particularly complicated outcomes. And similarly, any mind imaginable—human, post-human or alien—must be there to be discovered, in the pool, in metamathematical stasis."

Flood grimaced. "The Friends of Wigner were prepared to destroy Jupiter to send a message to the Ultimate Observer. Now this lunatic believes she can find the Observer in a tank of light."

"Show some respect," Stillich said sharply.

"But whether or not she ever achieved her goal, she is in danger of unleashing much greater threats on humanity. For some of the minds in there are not content with stasis, with waiting to be discovered. Look at this." He summoned up a Virtual of his own. "We've been tracking this for years. Decades. We have our spies, in Sol system. Look at this. It's a neutrino scan we made from the Freestar just hours ago."

It took Stillich a moment to work out that he was looking at a cross-section of the Earth, deep below the granite raft of Manhattan, and the imperial bunker. And down there, swimming in the mantle, was a shape, perhaps organic, perhaps artificial, a winged shape like a stingray, like a sycamore seed.

"It isn't fully formed," Flood said grimly. "Not fully operational. But it soon will be."

Kale asked, "What is it?"

"In the Friends' accounts of their dark future, there are hints of a race even more threatening to mankind than the occupiers of Earth from whom they fled. A race called—" His pronunciation was uncertain: “Chee-lee, Zee-lee. They, or their potentialities, are lurking in the logic pool. And they are trying to break out."

"How?" Kale snapped. "By constructing this ship, deep in the Earth? How are they doing that?."

"We have no idea," Flood said. "Our only concern was to stop it, before this ship bursts from the Earth like a bird from its egg. I mean, this is a threat so potent it is trying to strike at us out of nothing more than a statement of the logical possibility of its own existence! If this thing had got out of the mantle, I don't imagine our four light years' separation would have saved Alpha system. Now do you see why it was necessary to wage this war? It wasn't just for our freedom from Shira's political domination. It was to free all mankind of this terrible threat—for Shira, your Empress from the future, was endangering all of us."

Stillich looked at the Admiral's grim face.

"Decision time," said Kale.

"Yes, sir. My view? It's not worth risking Earth to save this project of the Empress's—"

"The Project is worth any price," Shira murmured. "Even that."

Kale turned to her. "Ma'am—we have no time. We must accept his terms. We can discuss the details of your abdication later—the legitimisation of an interim government ... " He turned to Flood. "You have won, star-farmer."

Flood picked up the nanotechnological box, and dropped it in the logic pool. It sank with barely a ripple, and then seemed to dissolve. Flood watched the pool, as the writhing metamathematical bifurcations withered, and the pale light began to die. "It is done."

Stillich said urgently, "And call off your relativistic attack dog."

Flood smiled. "Done."

"None of this is real," Shira murmured. She rolled back into the shadows.

Kale faced Flood. "You will pay for all you have done."

Flood gazed at him, his eyes full of regret. "Oh, I have paid, soldier. Believe me, I have paid."

And then the bunker shuddered, and a wave like a tide pulsed through Stillich's gut.

Kale staggered. "What was that?"

When Stillich had recovered, Shira was gone.

S-Day plus 11

Asteroid Belt

Earth was so close now that Densel Bel could see it, an image magnified and heavily corrected for relativistic distortions, suspended over his head—he could see it in real time, a blue marble, achingly beautiful, and yet scarred by war. But he could never touch it. The vast pulse of kinetic energy that had been injected into this ship by years of GUTdrive acceleration separated him from his home world just as much as if he had been stranded in another universe.

Only subjective minutes remained before his life ended, and Earth died with him.

Once more Flood appeared before him. "It's over," he said, smiling.

"What is?"

"The war. Shira is abdicating—we are free. Now you must destroy the Fist Two."

"Me? Why me?"

"This was your purpose, Densel Bel. You are my failsafe. I needed somebody on board who I knew would terminate the mission, even at the cost of his own life. And that's you, a man loyal both to Earth, where you were born, and Footprint, where you have your family. You have the authority. Just say aloud, 'let it end'. The AI will do the rest. Goodbye, Densel Bel. I hope you feel the sacrifice you are making is worth it."

"Flood. Wait—"

"Yes?"

"Would you have done it? Would you have let the Fist strike the Earth?"

"Oh, yes. To stop what Shira was doing—believe me, there was no choice. Good luck, Densel Be!." He broke up into a cloud of pixels and disappeared.

Densel Bel looked up at the blue Earth, and thought of Su-su and Fay. "let it end."

Light flared, an instant of intense white pain—

S-Day plus 7 months

Earthport

The flitter rose from Earth like a stone thrown from a blue bowl. The little cylindrical craft tumbled slowly as it climbed, sparkling.

Peering out from the rising flitter, Stillich had to admit that the Freestar, which he had come to inspect on behalf of the Navy, looked spectacular, with the newly constructed wormhole Interface, a bright blue tetrahedron with milky-gold faces, slung beneath its angular spine. When Flood and his crew returned to Alpha system in a couple of months, they would take the grudging good wishes of Earth's interim government with them, and the business end of a new wormhole, which would link the worlds of Alpha and Sol forever.

"Or until the next political crisis," Flood said dryly.

"There is that."

"Look—here comes another shipment of green muck from Titan."

It was a cargo pellet slung from Titan that had crossed the system unpowered, and now made an entry into Earth's atmosphere, cutting a bright contrail across the blue sky. This crude shipment method was an interim emergency measure, until the great space elevators were hung in the sky once more.

"Not 'green muck'," Stillich said. "Algal concentrate."

Flood pulled a face. "Next time you visit Footprint, be my guest at dinner."

"That might be some time away," Stillich said gently.

They both knew that was likely to be true. Too many had died, on Earth and elsewhere, for the populations of Sol system to forgive their colonial cousins for the war, whatever the retrospective justification in terms of Shira's murky crimes.

But it would come in time, Stillich knew. Already Earth was recovering, as people and machines laboured to repair the damage done, and the vast resources of space were reattached to the damaged planet. And likewise Sol system was making conciliatory gestures to the starborn. The Facula was en route back to Tau Ceti, taking the abducted colonists home. Stillich had made sure Pella was on that mission. She was a bright officer, but she needed to acquire the humanity that informed good judgement

"I saw your report on Shira's escape," Flood said now. "You were serious in your conclusions?"

"There's no real doubt about it." Shira had stashed many treasures from her lost future down in that bunker, and among them was what appeared to be a transdimensional transport system: Shira had disappeared from the bunker by stepping sideways into one of the universe's many extra compactified dimensions. "If that doesn't qualify as a 'hyperdrive' I don't know what does."

Flood shook his head. "She had a hyperdrive. And she kept it to herself all these centuries, while the rest of us limped across the Galaxy in sublight GUTships. Just so she had a last-resort escape hatch. How selfish."

"Maybe it's just as well. Anyhow I guess we are due to acquire the technology in a few centuries. Certainly it will transform the face of war." Stillich and Flood were both key witnesses at an inter-governmental inquiry into the course and conduct of the war, an experience Stillich suspected had increased both their understandings. "When you think about it, an interstellar war fought out with sublight drives is right at the limit of the possible. For a start you need a strong reason to do it; almost nothing is worth fighting such a campaign for."

Flood grunted. "You should read more history. Our fear of what Shira was up to was comparatively rational as a casus belli. Another global threat, experiments with vacuum energy, which could destabilise the entire universe, say, might be another. But horrific wars have been fought over splinter-fine differences in ideologies. look up the crusades some time."

"But when we get hyperdrive," Stillich said, "and as a consequence—perhaps—we get an authentic first alien contact, rather than these dark hints and glimpses from the future, we might soon see a transformation both of our means of fighting war, and of our choice of opponents. This might be remembered as mankind's last great conflict."

"The end of human war?" Flood laughed. "I knew you were imaginative, Stillich. I didn't have you down as a dreamer ... "

An alarm chimed, as the flitter prepared to dock with the Freestar. Stillich straightened his uniform, preparing for duty.

As it turned out, Flood was wrong.

It was only a few years later that Pella, en route to Tau Ceti, sent Stillich a packet message to announce contact with an alien species. He took the call in his apartment in the clouds over London.

"As far as we can tell they are aquatic group-mind multiple creatures. Fish-like. They have an interstellar network of trading colonies. Their name for themselves"—a thin squeal, heavily processed from the creatures' own sounds, 'Ss-chh-eemnh'—means something like the Wise Folk. Rather like Homo sapiens. Captain, here's the thing. They were heading for Sol system! They picked up some kind of signal from Shira's escape. The hyperdrive she used must have been one of their drives, or a human derivative. The question is, sir, how our descendants managed to take such a prize away from the Ss-chh-eemnh ... "

Everything was different, then, Stillich thought; this was a discontinuity in human history. He looked away from the busy bowl of the city, to the silent stars, wondering what came next.