Xeelee: An Omnibus: Raft, Timelike Infinity, Flux, Ring

by Stephen Baxter

  ‘Maybe,’ Trapper-of-Frogs said slowly, ‘but I’ve been thinking about that. I mean, the Planners could have killed us earlier, when we were strung out along the Deck. Couldn’t they?’

  Mark frowned. ‘They fired over us. Maybe they were trying to warn us.’

  ‘Maybe.’ Trapper-of-Frogs nodded grudgingly. ‘Or maybe they were trying to hit us - but couldn’t. Watch this.’

  She pulled a dart from the pouch at her waist and raised her blowpipe to her lips. She spat the dart harmlessly into the air, on a flat trajectory parallel to the Deck.

  Morrow, bemused, tracked the little projectile. It rapidly lost most of its initial speed to the resistance of the air, but its path continued flat and even, still parallel to the Deck. Eventually, Morrow supposed, it would slow up so much that it would fall to the Deck, and . . .

  No, it wouldn’t, he realized slowly. The GUTdrive was shut off: there was no gravity. Even if air resistance stopped the dart completely, it still wouldn’t fall.

  ‘When the gravity first disappeared,’ Tracker said, ‘I couldn’t hit a damn thing. I seemed to aim too high, every time. I quickly worked out why: even over quite short distances, gravity will pull a dart - or a cross-bow bolt - down a little way. I’ve grown up compensating for that, allowing for it unconsciously when

  I aim at something.

  ‘In the absence of gravity the dart just sails on, in a straight line, until it hits something.’ She hefted the blowpipe. ‘It took me hours of practice before I felt confident with this thing in zero-gee; it was like learning from scratch all over again.’

  Mark was nodding slowly. ‘So you think the Planners’ bowmen meant to hit us.’

  ‘I’m sure of it. But they shot too high. They haven’t learned to adjust to zero-gee; they certainly didn’t allow for it when they shot at us.’

  Constancy-of-Purpose cupped her chin. ‘Maybe you’re right. But I don’t see how that helps us. Even if their aim is a little off, there are enough of them to blanket us with bolts if we try to get too close.’

  ‘Yes,’ Mark said, some excitement entering his artificial voice, ‘but maybe we can use Trapper’s insight in another way. She’s right; the Planners - everyone in that building - are failing to learn how to cope with the absence of gravity. In fact, they seem to be denying that the absence even exists.’ He glanced around, staring at the tracery of ropes they’d laid from the access ramps as if seeing them for the first time. ‘And so have we. Look at the way we’ve travelled - abseiling across the floor, sticking to the familiar two dimensions to which gravity restricts us.’

  Morrow frowned. ‘What are you suggesting?’

  Mark raised his face to the iron sky. ‘That we try a little lateral thinking . . .’

  At the origin of the weak, ancient signal Louise and Spinner found a worldlet. It was a dirty snowball three hundred miles across, slowly turning in the outer darkness.

  When Louise bathed the worldlet with spotlights from her life-lounge, broken ice shone, stained with splashes of colour: rust-brown, grey.

  This lost little fragment followed a highly elliptical path, each of its distorted journeys lasting a million years or more. Its closest approach to the Sun came somewhere between the orbits of Saturn and Uranus, while at its furthest it got halfway to the nearest star - two light-years from the inner worlds.

  ‘Bizarre,’ Louise mused. ‘It’s got the orbital characteristics of a long-period comet - but none of the physical characteristics. In morphology it’s more like a Kuiper object, like Port Sol. But then it should be in a reasonably circular orbit . . .’

  Spinner-of-Rope peered out of her cage at the dark little world, wondering what might still be living down there.

  Here and there, in pits in the ice, metal gleamed.

  ‘Artefacts,’ Louise said. ‘Can you see that, Spinner? Artifacts, all over the surface.’

  ‘Human?’

  ‘I’d guess so. But I don’t recognize anything. And I doubt if there’s much still working . . .

  ‘I’m taking radar scans. There are hundreds of chambers in there, in the interior. And our beacon’s somewhere inside: still broadcasting on all wavelengths, with a peak in the microwave range . . . Life knows what’s powering it.’

  ‘Is this ice-ball inhabited? Is there anyone here?’

  ‘I don’t know.’ Spinner heard Louise hesitate. ‘I guess I’m going to have to go down to find out.’

  The pod’s small jets flared across the worldlet’s uneven surface as Louise descended. Spinner watched; the pod was the only moving thing in all of her Universe.

  ‘I’m close to the surface now,’ Louise reported. ‘I’ll level off. They certainly made a mess of this surface. I think these artifacts are sections of ships, Spinner. Not that I can label much of it - so much of this technology must be tens of millennia beyond us . . . Lethe, I wish we had the time to spend here, to study all this stuff.

  ‘But at least it’s human.’ Her voice sounded strained. ‘The first traces of humanity we’ve found in the whole damn System, Spinner.

  ‘I think people landed here, and broke up their ships for raw materials to occupy the interior.

  ‘I’m going to land now. I see what looks like a port.’

  Louise couldn’t find any way to open the wide, hatch-like port to the interior. Instead, she had to erect a plastic bubble to serve as an airlock over the port, and cut her way through, working slowly in the microgravity.

  ‘All right, I’m in.’ Her breath was scratchy, shallow - almost as if she were whispering, Spinner thought. ‘It’s dark here, Spinner. I have lamps; I’m going to leave a trail of them, as I go through.’

  Spinner, listening in her cage, prayed that nothing bad happened to Louise down there. If it did, what could she - Spinner - do? Would she have the courage even to try a landing on the ice worldlet?

  Doubt flooded her, a feeling of inadequacy, of being unable to cope . . .

  You’ll manage, Spinner-of-Rope.

  That same dry, sourceless voice.

  Strangely, her fears seemed to subside. She glanced around; of course, she was alone in the cage, with the nightfighter suspended passively over the ice worldlet. But still - again - she had had the impression that someone was here with her. She couldn’t see him, or her - but somehow she knew there was nothing to fear; she sensed a massive, comforting presence similar to her own, lost father.

  But still - hearing voices? What in Lethe is going on inside my head?

  ‘ . . . Lots of chambers,’ Louise said a little breathlessly. ‘They are boxes, carved out of the ice and plated over with metal and plastic. A bit cramped . . . There is air here, but foul; I won’t be breaking my suit seal. This was definitely a human colony, Spinner. But it’s all - neat. Tidy; abandoned in an orderly way.

  ‘I guess they took a long time to die. They had time to clear up after themselves - to bury their dead, maybe, even, as they withdrew. I guess they went deeper as their numbers dwindled, towards the centre of the world . . . It’s kind of dignified, don’t you think? There are no signs of panic, or conflict. I wonder how we would behave, in the same circumstance. Spinner, I’m going on now.’

  Later: ‘I’m in a deeper layer of chambers. I think I’ve found the source of the signal.’ She was silent for a while. Then, ‘They sure built this to last.’

  ‘Well, they got that right.’

  ‘I still can’t identify what’s powering it . . . I guess one of the ship’s GUTdrive plants on the surface. I think they used nanobots to maintain the beacon, Spinner. Maybe they adapted AS nanobots from their medical stores.’ Her tone of voice changed, subtly, and Spinner imagined her smiling. ‘They were determined to enable this to survive. But it’s been millions of years . . . and the ‘bots have made a few cumulative mistakes. The damn thing looks as if it’s melted, Spinner. But it’s still pumping out its signal, so we can’t criticize too much . . .’

  ‘Louise,’ Spinner asked slowly, ‘why were these people here? What
were they trying to do?’

  Louise thought for a while. ‘Spinner, I think they were trying to escape.’

  This ice-world was typical of the small, subplanetary bodies which could once have been found throughout the Solar System, Louise said, shepherded into orbital clusters by the major planets.

  ‘But,’ Louise said, ‘the orbits of many of those little bodies were only semistable . Their orbits were intrinsically chaotic, you see . . . That means, over a long enough time period the minor bodies could move out of their stable pathways. They could even fall into the gravity wells of the major planets and be flung out of the System altogether. It’s a form of evaporation - an evaporation of worlds and moons out of stellar systems. In fact, over a long enough scale - and I’m talking tens of billions of years now - the same thing would happen to the major planets too - and to stars, which could evaporate out of their parent galaxies . . . If,’ she went on sourly, ‘they had ever been given the chance.’

  ‘So you think this little world just evaporated away from Sol, gravitationally?’

  ‘No . . . not necessarily.’

  Louise speculated about the closing stages of the Xeelee conflicts. She imagined mankind trapped within its home System, sliding towards the final defeat. Towards the end, even communication between the worlds might have broken down. Humanity would have been reduced to isolated pockets, cowering under the Xeelee onslaughts.

  But some might have seen a way out - a way to try to escape the final investing of the System by the Xeelee.

  Louise said, ‘Imagine this little worldlet following its semi-stable path - say, between the orbits of Saturn and Uranus. It wouldn’t have taken much to push it far enough out of its orbit to bring on orbital instability. And once equilibrium was lost, the drift away from the standard orbital elements could have been quite rapid - say, within a few orbits - and the decay wouldn’t have required any further deliberate - and observable - impulses, perhaps.’

  Silently, all but invisibly to anyone watching, the little world, with its precious cargo of cowering, fearful humans, had looped through its increasingly perturbed orbit, falling at last - after many orbits, perhaps covering centuries - into the gravitational field of one of the major planets.

  Then, finally, the worldlet was slingshot out of the Solar System.

  ‘If they’d got it right,’ Louise said, ‘maybe it would have been a viable plan. If. These people were going to the stars, by the lowest-tech way you can imagine. It would have taken tens of thousands of years to get to even the nearest star - but so what? They had tens of thousands of years to play with, thanks to AS - or the equivalent they’d developed by then. And locked up in the ice of the worldlet there was probably as much water as in the whole of the Atlantic Ocean . . . Going to the stars in an ice moon was certainly a better chance than staying here to be creamed by the Xeelee with the rest - it was a viable way to get out of all this, all but undetectable.

  ‘The scheme obviously attracted support. You can see the bits of ships, littering the surface . . . People must have fled here, quietly, from all over the collapsing System. The mission was a beacon of hope, I guess.

  ‘But—’

  ‘But what?’

  ‘But they got it wrong.

  ‘I’m going to go deeper now, Spinner.’

  ‘Be careful, Louise.’

  There was a long silence, broken only by the sound of Louise’s shallow breath. Spinner filled her faceplate once more with cool, green leaf-light and stared into it, trying not to imagine what Louise was finding, down there inside the little tomb-world.

  At length, Louise said: ‘Well, that’s it. I guess I’m here: the last place they occupied . . . the one place they couldn’t tidy up after themselves.’

  Spinner stared into green emptiness. ‘What can you see?’

  ‘Abandoned clothes.’ Hesitation. ‘Dust everywhere. No bones, Spinner; no crumbling corpses . . . you can put your imagination away.’

  After five megayears, there would only be dust, Spinner thought: a final cloud, of flakes of bone and crumbled flesh, settling slowly.

  ‘If they left records, I can’t find them,’ Louise said. She sounded as if she were trying to be unconcerned - to maintain control - but Spinner thought she could hear fragility in that level voice. ‘Perhaps there’s something in the electronics. But that would take years of data mining to dig out, even if we could restore the power. And we’re probably looking at technology a hundred thousand years beyond ours anyway . . .’

  ‘Louise, there’s nothing you can do in there. I think you should come out.’

  ‘ . . . Yes. I guess you’re right, Spinner-of-Rope. We don’t have time for this.’

  Spinner thought she heard relief in Louise’s tone.

  The little Northern pod clambered up from the worldlet’s shallow gravity well, towards the Xeelee craft.

  Louise, safe inside her life-lounge, said: ‘They couldn’t control the slingshot well enough. Or maybe the Xeelee interfered with their plans.

  ‘They weren’t thrown out of the System as they’d planned, on an open-ended hyperbolic trajectory; instead they were put into this wide, and deadly, elliptical orbit - an orbit which was closed, taking them nowhere, very slowly.

  ‘I guess they tried to stick it out. Well, they’d broken up their ships; they had no choice. Maybe if we had time for a proper archaeological study here we could work out how long they lasted. Who knows? Hundreds of thousands of years? Maybe they were hoping for rescue, for all that time, from some brave new future when humans had thrown out the Xeelee once more.

  ‘But it was a future that never came.

  ‘By the time they set up their beacon, their final plea for help, they must have known they were through - and that there was nobody to come to their aid.’

  ‘Nobody except us.’

  ‘Yes,’ Louise growled. ‘And what can we offer them now?’

  ‘What about the beacon?’

  ‘I shut it down,’ Louise said softly. ‘It’s served no purpose . . . not for five million years.’

  Spinner sat in her Xeelee-crafted cabin, watching the grim little tomb of ice turn beneath her prow. ‘Louise? Where to now?’

  ‘The inner System. I think I’ve had it with all this bleakness and dark. Spinner-of-Rope, let’s go to Saturn.’

  19

  Surrounded by swooping photino birds, Lieserl sailed around the core of the Sun. She let hydrogen light play across her face, warming her. The helium core, surrounded by the blazing hydrogen shell scorching

  its way out through the thinning layers, continued to grow in the steady hail of ash from the shell. Inhomogeneities in the giant’s envelope - clouds and clumps of gas, bounded by ropes of magnetic flux - moved across the face of the core, and the core-star actually cast shadows outwards, high up into the expanding envelope.

  The photino birds swept, oblivious, through the shining fusion shell and on into the inert core itself. Lieserl watched as a group of the birds broke away and sailed off and out, to their unknowable destination beyond the Sun. She studied the birds. Had their rate of activity increased? She had the vague impression of a greater urgency about the birds’ swooping orbits, their eternal dips into the core.

  Maybe the birds knew the ancient human spacecraft, the Northern, was here. Maybe they were reacting to the humans’ presence . . . It seemed fanciful - but was it possible?

  The processes unfolding around the Sun were quite remarkably beautiful. In fact, she reflected now, every stage of the Sun’s evolution had been beautiful - whether accelerated by the photino birds or not. It was too anthropomorphic to consider the lifecycle of a star as some analogy of human birth, life and death. A star was a construct of physical processes; the evolution it went through was simply a search for equilibrium stages between changing, opposing forces. There was no life or death involved, no loss or gain: just process.

  Why shouldn’t it be beautiful?

  She smiled at herself. Ironic. Here she was, an
AI five million years old, accusing herself of too much anthropomorphism . . . But, she thought uneasily, perhaps her true fault lay in not enough anthropomorphism.

  The sudden communication from the humans outside - the whispers of maser light which had trickled down the flanks of the huge, dumb convection cells - had shaken her to her soul.

  She’d undertaken her cycle of messages, she suspected strongly, because she was driven to it by some sinister bit of programming, buried deep within her: not out of choice, or because she believed she might actually get a reply. So she’d packed her data with pictures of herself, and small, ironic jokes - all intended, she supposed, to signal to herself that this wasn’t real: that it was all a game, unworthy of being taken seriously because there was no one left out there to hear.

  Well, it seemed now, she’d been wrong. These people - of her own era, roughly, preserved by relativistic time dilation in their strange ship, the Great Northern - had returned to the Solar System.

  And they were - she’d come to believe - people who didn’t approve of her.

  They hadn’t said as much, explicitly. But she suspected an inner coldness was there, buried in the long communications they exchanged with her.

  They thought she’d lost her objectivity - forgotten the reason she was placed in here in the first place. They thought she’d become an ineffectual observer, seduced by the rhythmic beauty of the photino birds.

  Lieserl was some form of traitor, perhaps.

  For the truth was - in the eyes of the men and women of the Northern - the photino birds were deadly. The birds were anti-human. They were killing the Sun.