Xeelee: Vengeance

by Stephen Baxter

  A few years younger than Poole, Miriam had brown eyes and hazel hair prematurely streaked with grey, cut low-gravity neat. Now she looked older, gaunt, exhausted. Poole insisted she let the ship’s medical suite treat her for any radiation damage within the hour. But she refused food and water. For now she just wanted coffee, and to sit.

  Eventually she said simply, ‘Thanks.’

  Nicola shrugged. Evidently she didn’t appreciate gratitude.

  ‘You need to go back to the wormhole, by the way.’

  Without questioning, Nicola laid in the course.

  Poole sat in a fold-out passenger chair. ‘We were told there were three survivors.’

  Miriam sucked coffee through a zero-gravity lid. ‘I’m the only one who made it. Bill Dzik and Melia . . . We were the last, we three. Most of Melia’s memory store had been uploaded; we had the rest of her in a core processor – a last-resort backup, a thing like a suitcase. The platform had already started to tilt. Melia wanted us to leave her behind, so we could escape on the scooters.’ She glanced at Nicola. ‘Low-gravity terrain-hopping vehicles—’

  ‘I can guess.’

  ‘Bill refused to dump her. So she charged the casing, and shocked him so he’d have to drop her. And while he was trying to get hold of her again, the platform tipped, and we had air tanks and other heavy-duty gear smashing through the partitions and raining down on us—’

  ‘Bill Dzik,’ Nicola said. ‘Never met the man, but a name to remember. The first human to die because of all this, the incursion through the wormhole. And Melia, the first artificial sentient.’

  Miriam nodded. ‘Much of her memory can be reconstructed. But she has gone, yes. So we failed.’

  ‘You did your best,’ Nicola said calmly, surprising Poole. ‘You came close to getting everybody out of there. What more could you do?’

  ‘Not screw up.’

  ‘Everybody screws up. Life’s not perfect.’

  ‘Well, it should be.’ Miriam had finished her coffee. Poole handed her his own carton. She started to drain it, like the first.

  ‘So,’ Poole said. ‘Why do we need to go back to the wormhole?’

  Nicola said, ‘I can tell you that. More chatter on the comms feeds. There’s a new development. Something else coming through. You need to be there.’

  ‘Us?’

  ‘Not us. You.’

  6

  The wormhole portal, when they got to it, was surrounded by a cloud of ships, a rough sphere. Many of these were GUTships of the classic design, each a gaunt pole topped and tailed by lifedome and lump of comet ice. Because of the threat of the quagma phantoms, the ships were immobilised save for their secondary attitude-control thrusters. But Poole knew that some of the ships, including flitters belonging to the UN’s Federal Police, might be armed.

  There was some contact from these ships as Crab Junior arrived, including a hail from Harry Poole and Shamiso Emry in the Hermit Crab, returned from Ganymede, somewhere in the crowd. Junior was allowed to pass through the cordon, and then to approach the wormhole portal at the centre of the cloud, the spiky tetrahedron, its sky-blue structure as innocent-looking as it had been before the sycamore seed entity had pushed its way through. Approach until they were closer than any other ship, Poole realised uneasily.

  And, finally, they confronted the new thing that had come through.

  It was another enigmatic, anonymous form: a sphere, silvered, maybe a couple of metres across. It had a kind of belt around its circumference, like a lanyard to which a bright green pendant was fixed.

  Miriam and Nicola, at the controls, studied this object with the flitter’s sensors.

  Poole just stared. ‘It looks like a cousin of those raindrops that came through with the sycamore seed.’

  ‘Don’t think so,’ Nicola said. ‘Actually more massive. That thing weighs a tonne. Not quite as dense as water . . .’

  ‘It’s nearly featureless,’ Miriam said, checking monitors of her own. ‘But you can see it’s rotating. Look at that lanyard around its equator. A lanyard with a pendant attached . . .’

  Wordlessly Nicola brought up an image of the ‘pendant’. It was a tetrahedron – small, only a few centimetres across, a green frame enclosing an empty space. ‘Curious,’ Nicola said dryly. ‘Wherever this thing came from, how could it know that this end of the wormhole ended in a tetrahedron?’

  ‘And curiouser yet,’ Miriam said, ‘according to the analysis by the UN observers, that green isn’t any old green. That’s chlorophyll green – Earth green.’

  Poole was feeling uneasy, increasingly so. The lingering sense of wrongness that he’d felt since the first emergence of the sycamore seed from the wormhole was now deepening drastically, spiralling down within him like an Anthropocene-era drill sucking the last dregs of oil from a well. ‘Maybe it’s a universal,’ he said. ‘Chlorophyll, I mean. Maybe under any sunlike star, with a carbon-based biosphere, the laws of chemistry dictate—’

  Nicola laughed. ‘Your biologist buddy Jack Grantt wouldn’t buy that. There are many ways to eat sunlight. And even if so, do you imagine that tetrahedral form is a universal too? You designed the portal. Why did you choose that configuration, anyhow? Why not a cube or—’

  ‘Because it looked – well, right. Aesthetically. I wanted my wormholes to be beautiful. We sat up all night sketching.’

  ‘So, an arbitrary choice?’ Nicola looked back at him. Given the news she was about to reveal to him, he would later reflect, she didn’t seem excited, or impressed. She said simply, ‘There’s something else. Your sycamore seed may not have spoken to us, but this spinning sphere is. Since it emerged. Across the electromagnetic spectrum, in neutrino pulses, even in gravity waves . . . A lot of trouble for a few words. Even if they are in Standard.’

  ‘Standard?’

  ‘She’s right,’ Miriam said, watching monitors of her own.

  ‘Just tell me,’ Poole said hoarsely.

  ‘Here’s a live broadcast, with a rough translation.’ Miriam touched an icon.

  The voice was flat, artificial, tinny. The intonation was odd, almost quaint, as if spoken by a non-Standard speaker, or as if this was some recording from the deep past. Poole found he needed the comms system’s simultaneous best-guess translation to make sense of it.

  ‘. . . Ambassador to the Heat Sink. I am here for Michael Poole. I am a Silver Ghost. That is, or will be, your name for us. Our kinds waged war for millennia. And yet I bear the Sigil of Free Humanity, as you can see. I have visited the tetrahedral cathedrals of the Wignerian faith of which you, Michael Poole, are a prophet. And at the centre of the Galaxy, on a world dedicated to the billions of dead of the Exultants’ war, there is a statue of you, Michael Poole. Two kilometres high. I have seen that statue for myself. I will be with you at Timelike Infinity, Michael Poole, where this burden will pass. I am known to my own kind as the Ambassador to the Heat Sink. I am here for Michael Poole. I am a Silver Ghost. That is, or will be . . .’

  The flitter shuddered, as if a mass had detached itself from the hull of the small craft.

  Then, through the window, Poole, disbelieving, saw a missile sail across space, silent, barely visible. It was a depth probe, he recognised, designed to hit a rocky asteroid or comet core at high velocity, to sample its deep interior. He knew it wasn’t intended as a weapon. But it would work as a weapon. It was streaking across the gap towards the drifting, spinning ‘Ghost’.

  And it had come from the Crab Junior.

  He glared at Nicola. ‘Why in Lethe did you do that?’

  ‘I didn’t.’ She was checking her displays. ‘There was an override . . . Harry. Your father fired the missile.’

  ‘What? This is my ship. He doesn’t have an override.’

  Miriam glared at him. ‘Are you sure? More to the point, why would he do this?’

  Nicola shrugged. ‘T
o secure the safety of mankind. Or some such. That’s what the public feeds are being told. Or possibly it’s because this Ghost thing named you, not him? You two need to talk about your rivalry issues, it’s not healthy.’

  Still the ‘Silver Ghost’ spoke. ‘I bear the Sigil of Free Humanity—’

  And Poole saw the projectile, at a comparatively low speed, penetrate the Ghost’s hide.

  ‘—the tetrahedral cathedrals—’

  The Ghost simply burst open.

  That shimmering skin ripped, shredded, and a mess of biology came tumbling out: red blood, quickly freezing; masses like organs, muscles; even a kind of rangy, long-limbed body, with recognisable torso and limbs, foetus-like, coiled up. And what looked like a vegetable mass, or perhaps something fungal, that had evidently packed the shell.

  Out of the dispersing mess that pendant came sailing, the green tetrahedron, still attached to a snapped lanyard.

  Nicola broke the silence. ‘I guess that souvenir is yours. You want me to go out and get it for you?’

  ‘Do it,’ he snarled. ‘Sooner that than leave it for Harry. Then let’s go to Gallia.’

  TWO

  ‘But the future is irrelevant.’

  ‘It is?’

  ‘Yes! If we can’t get through the present.’

  Tom and Michael Poole Bazalget, ad 2047

  7

  Nicola guided the flitter in towards Gallia Three, working her way through a crowd of other refugee-laden craft: more flitters, larger fusion-drive scows – slow freighters designed to carry cargoes of ore and ice – even a couple of gaunt GUTships, nudged this way by their manoeuvring and attitude control systems. One of these ships had brought Harry here, Poole knew. Not for the first time in his life, his father had overtaken him.

  And Gallia Three was gradually revealed.

  Gallia was a squashed ball of dirty comet ice about a third of a kilometre across – an oblate spheroid, like Jupiter itself, shorter from pole to pole than it was fat at the equator. The whole turned rapidly on that short axis; Poole, instinctively counting, estimated it completed a rotation in about half a minute. The outer crust was a dirty crimson-black, thanks no doubt to a layer of complex hydrocarbon molecules in the ice created by hundreds of years of Jovian radiation and inner-System sunlight. But as the spheroid turned, Poole glimpsed flashes of Earth green shining from windows, breaks in the black, there and gone. It was an oddly nostalgic view – at least, Poole supposed, if you had grown up on Earth.

  This nucleus was only the heart of a wider mechanism. A lacy, dodecahedral frame was pinned to the habitat at its rotation poles. And to the frame was attached, by glimmering guide cables, an immense mirror, more than five times the diameter of the habitat itself. Reflected sunlight splashed on receptor panels at the habitat’s poles. Poole saw repair bots crawling over the mirror, like beetles on glass, sending slow ripples washing across the gleaming surface.

  Nicola was looking stuff up. ‘They use that mirror-sail, not just for catching sunlight for their fields and forests, but actually as a sail, for position and momentum control. They tweak their orbit; they don’t come too close to Jupiter, for instance. And across an orbital path that spans four astronomical units there’s time to do all the tweaking they need. What an antiquated, ramshackle—’

  ‘I’ll tell you what’s ramshackle, child, and that’s your imagination.’ Highsmith Marsden’s Virtual head flared into existence once more above the flitter’s comms console. ‘Old we might be, crusty we might be, but right now we’re the only safe haven for you and your wretched bands of miners and digger bots, aren’t we? Now, if you want to come any closer you’re going to have to shut down your fusion drive – you can manoeuvre with any chemical-propellant thrusters you have – and you can shut down your comms too. Passive sensors only; no pinging of my hull. We’re running silent here, and if you keep wandering around lit up like an Earth Day display you can go dive into Jupiter itself for all I care. Is that clear enough?’

  Poole tried to reply. ‘Professor Marsden—’

  ‘Oh, and by the way, that alien artefact you picked up—’

  ‘The amulet,’ Nicola said.

  ‘Amulet?’ Marsden mused. ‘I haven’t heard it called that before. An old word: an object that brings its wearer power or protection. Maybe that’s appropriate. Don’t even think of bringing it into my habitat.’

  The link was broken; the talking head disappeared in a cloud of pixels.

  Nicola sighed. ‘I want to be like him when I grow up.’

  ‘Paranoid old relic.’

  ‘But he has a point. Let’s do as he asks.’

  The dock was situated at one non-rotating pole of the habitat, and Poole had to admire the skill with which Nicola guided the Junior, unpowered save for a few puffs of chemical-propellant exhaust, through a forest of structural beams, antennae and sensor gear. The mechanisms of dock and airlocks were scuffed and much patched. Poole wondered how much of the fabric of this ancient habitat was original.

  Once they were through the lock they faced a brightly lit inner space, a squashed sphere with a belt of Earth-green landscape plastering the equatorial region. Sunlight shone up into the hab through radiation-proofed windows set in the artificial ground. The air was threaded with ropes and struts along which people and machines briskly swam, hauling equipment and cargo boxes. Harry Poole was already coming up to meet them at the axial lock, pulling his way along a cable. Poole could see Marsden himself bustling up, a good way behind, his shock of white hair unmistakable.

  There was a tube of cloud along the axis, slowly churning. The landscape knotted up around the far pole, pale with mist.

  Nicola was staring around with a reasonable facsimile of wonder, despite apparent efforts to maintain a veneer of scepticism. ‘I wonder if it rains in here.’

  ‘I doubt it.’ Poole tried to remember what he knew of the Gallias. ‘Not big enough. Sprinklers, though.’

  Harry reached them, breathing a little heavily after the effort of dragging himself through the air; AS-youthful or not, Poole thought wryly, he had never been one for physical exercise. He shook his son’s hand. ‘Michael. Lethe, I’m glad you made it. How are you feeling?’

  ‘I’m feeling I can’t remember the last time you shook my hand, Harry. The last time you bothered to show up physically.’

  Nicola seemed entirely unoffended to be ignored. She merely grinned, cynically. ‘Ah, but you’ve never been so famous before, Michael. That thing, the mercury-drop alien that came through the wormhole – it named you, not him. Which is why you shot the Ghost out of the sky, right, Harry?’

  Harry glared at her. He never looked older, Poole thought, than when he was angry. ‘You still here?’

  Poole still felt stunned by the memory. ‘Why did you destroy it, Harry? Firing a missile from my ship.’

  ‘Because it seemed a good idea at the time. Highsmith Marsden agrees, actually. We’d already let strangers into our Solar System. Enough’s enough. We didn’t need any more.’

  ‘You’d make such a decision, on behalf of all mankind?’

  ‘Sure. If I’m the one on the spot. Everybody was watching, by the way. The whole incident. The news feeds, the comment channels – they’re calling it the Wormhole Ghost. It’s a frenzy. They are talking about you too, Michael.’

  ‘Oh, good.’

  ‘And there’s endless speculation about what this incursion means for mankind.’

  Poole asked dryly, ‘And what it means for the family?’

  Nicola grinned again. ‘Now who’s the cynic?’

  ‘It’s a heck of a wave,’ Harry said. ‘And it’s a wave we have to ride, son.’

  ‘A wave that’s likely to come crashing down on all your pretty heads!’

  This was Highsmith Marsden, climbing up at last, with that glowering, evidently habitually angry face now red wit
h exertion. He had a barrel chest, not a trace of fat about the belly, and muscles that bulged under a pale blue coverall. His arms and legs looked equally powerful, an odd symmetry. This was a body adapted for hard work in low gravity, Poole realised: the physique of a deep-space farmer. And, despite his obvious physical age, whether AS-preserved or not, Marsdsen seemed a lot fitter than Harry.

  He was still talking.

  ‘Worst case, following this incursion, is some kind of existential threat to mankind. A threat posed by agents of nature unknown, origin unknown.’ He looked Michael Poole up and down. ‘And since, unlikely as it seems now that I’m actually in your underwhelming physical presence, you were actually named by that spinning wormhole alien, you yourself, Michael Poole, may be a source of that threat, or a focus, whatever you say or do. Let’s get on with it. Follow me.’ He turned and scrambled along another rope that led away from this axis, and back down towards the habitat’s curving hull.

  The rest prepared to follow, more clumsily.

  Marsden called over his shoulder, ‘I’ve been speaking to your colleague, by the way. Miriam Berg. Sensible young person.’

  Miriam had gone ahead to this place in a fast one-person skimmer, to help with the arrangements for settling the refugee population from the Io facilities.

  Poole said, ‘I’m glad one of us impressed you. So what do you think we should do?’

  ‘Obviously, work out how to establish a stable human breeding population in a stealthed space habitat.’

  Nicola raised her eyebrows. ‘On any other day that would be an odd thing to say. Now, which way up am I supposed to be when I climb this rope . . .?’

  8

  It turned out not to be a foolish question.

  At first, following Marsden’s example, Poole pulled himself head first ‘up’ the rope, and so towards the curving landscape ‘above’ his head. But as they moved away from the spin axis it soon felt as if they were falling upwards, a disconcerting sensation. Poole hastily swivelled around, so he was drifting down feet first, slow as a snowflake, guided by touches on the rope.