Starfall

by Stephen Baxter

  "No, sir."

  "Why? Are they going to bypass Sol system altogether?"

  "I don't think so, sir," Pella said. "Right now their best-guess trajectory takes them straight to Earth—although they're moving so fast they're hard to track, even harder than the decelerators. By the time they reach Sol system they'll be running at only two per cent under lightspeed. So when we see an image like this, light-months old, it's not necessarily a good projection of where the ships are right now."

  "What can their purpose be, if they don't stop?"

  Pella took a breath; Stillich nodded to her, having already been briefed on this. "They may be relativistic missiles."

  Kale stared at her. "Are these ships manned?"

  "As far as we can tell," Stillich said.

  "A suicide mission, then. Do we have any defence?"

  "We're working on it, sir— "

  "There has to be a way to stop these fuckers before they get here. Throw a screen in their way—overwhelm their erosion shields, their laser defences. How about that? You could blow up a Kuiper object."

  "Sir, they're coming from out of the ecliptic," Pella said. "The plane of Sol system where most of the mass—"

  "I know what the ecliptic is, Commander," Kale said coldly. "Well, find a way." He peered at the images, pretty emblems behind which lay the capacity for huge destruction. "I never conceived anybody would launch such a weapon. I should have listened to you earlier, Stillich; you're thoroughly vindicated. What worries me now is what else we haven't thought of. The difficulty we have is that we've all been trained to serve a Navy that has for centuries acted in a policing role. We're no experience in fighting pitched battles—we aren't used to thinking this way. What about a second echelon? Is there a second fleet on the way after this dozen?"

  "We don't think so," Stillich said. "There simply can't be more serviceable GUTships out there. We think they've thrown at us everything they've got."

  "Well, that's something. Beat this lot and the war is won." He glared at Pella. "So what else have you got?"

  Pella tapped hastily at her data desk. "The results of the latest echo bomb." The Virtual tank cleared, to be replaced by a ghostly outline of Sol system out to the Kuiper belt, with the orbits of the inner planets traced concentrically at its tight heart.

  An echo bomb was a powerful detonation that sent an X-ray pulse out in all directions. Echoes indicated the location of any artefact in Sol system more than a metre across, out to dozens of astronomical units. The objective was, by screening out all known objects, to detect the coming of the unknown. The three-dimensional field filled up with markers, but Pella cleared most of them away, leaving the field empty save for a curtain of needle shapes at one side of the Virtual tank, and a misty sphere the size of a pea, out beyond the orbit of Pluto.

  "No new intruders, sir," Pella said. "It's taken a few iterations of this exercise to complete the labelling of all friendly items, and—"

  "I understand the principle." Kale pointed to the needles. "These are our ships."

  "Yes, sir," Stillich said, "mostly Navy interstellar cruisers—everything we have, save for those too remote from Sol to recall—and some commercial vessels, requisitioned and adapted. You can see that we have twenty-five ships, more than twice the aggressors' fleet. And you can see that we've deployed them as a screen, covering the geodetic between Sol and Alpha."

  "Hmm."

  Stillich said, "Sir, if we can keep them out of the system altogether—"

  "The trouble is, Captain, if the Alphans break through this defensive crust of yours, our GUTships once bypassed are going to be quite useless." Kale shook his head, black hair speckling the grizzle of grey. "I'd suggest you explore alternative deployments—deeper defence strategies. Let them come all the way into the heart of Sol system if they like. As you said, we may be able to dream up ways to hit them when they round the sun. It won't matter as long as we down them in the end."

  Pella coughed. "I don't think the Empress Shira will like that idea, sir."

  Kale said, "The Empress has delegated the fighting of this battle to us." He pointed to the pea-sized ball. "And what's this?"

  "Just a routine long-period comet," Pella said. "We can see from the radar reflections that its surface hasn't been modified by previous interactions with the sun. We've been tracking it since it started its fall in from the Oort cloud. It's inert." She smiled. "It ought to make a pretty show later in the year. Morale booster. "

  "'Just a comet'," Stillich said. "And yet it arrives just as the first interstellar invasion of Sol system ever attempted is showing up in our sensors. Let's assign a GUTship to track it."

  Pella glanced at Kale. "Captain, we only have twenty-five ships. To pull one out of the line for a comet—I told you, it shows no threat signatures at all—"

  Kale clapped a heavy hand on Stillich's shoulder. "For once I agree with your Number One. We don't have the resources to go shadowing inert blocks of ice. Forget it." He turned to leave. "Call me if anything else shows up."

  "Sir." Stillich stared at the comet, still unsure. But surely the Admiral was right in his general judgement that you had to devote your limited resources to tackling verifiable threats. "Get rid of it, Pella."

  Pella touched the Virtual of the comet with a fingertip, thus labelling it as a 'recognised' object, and it winked out of existence.

  "So, Number One," Stillich said. "What's next?"

  AD 4820

  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 dea
d 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."

  AD 4820

  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.

  AD 4820

  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 bl
ue 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.