Xeelee: Vengeance

by Stephen Baxter

  The descent got easier yet about forty metres down from the hub, where the ropes met a kind of grand, sweeping staircase, one of several set out radially around the axis point. When Poole tried standing, it felt as if the gravity was about lunar strength – a healthy fraction of Earth’s. As Poole had spent more than a year on the Moon, supervising an upgrade of the Copernicus GUT energy accelerator, this felt familiar. Once he’d got his balance he bounded confidently down the steps after Marsden, Nicola and Harry. And by the time he’d caught them up, the gravity was feeling stronger yet.

  ‘So,’ he said, as they walked on. ‘A breeding population? You have the room in here?’

  Marsden glanced at him. ‘Well, we should. Current population one hundred, capacity for five hundred. You understand the theory of the station. Years-long unpowered cruises from Earth to Jupiter. The Gallias were remote descendants of the Aldrin cyclers that once connected Earth to Mars: an economical way to achieve interplanetary travel. And the Gallias necessitated, by design, long-term self-sufficiency.’ He gestured at the landscape that was now unfolding before them. ‘Hence all this.’

  Looking straight ahead, Poole saw a green swathe of parkland broken by small lakes, with clusters of cabins built of what looked like bamboo. It was a convincingly Earthlike vista. But the green landscape rose up on either side, so that it was as if they were walking down a mountain pass into a tremendous valley – a valley with walls that rose like great waves to close over their heads, behind that axial tube of fluffy cloud. Those windows in the ground cast sunlight up through the moist air to splash on the habitat’s far wall; the shadows were peculiar.

  ‘Nice place for a vacation,’ Nicola said. ‘But it wouldn’t be a vacation to live here, would it?’ She glanced pointedly at Marsden’s own muscular body. ‘I’m no historian, but didn’t the age of farming end – Lethe, I don’t know, by the thirtieth century?’

  ‘More like the twenty-seventh,’ Poole said.

  ‘You would know,’ she murmured. ‘I expect your ancestors took out the patent on the first food machines, right?’

  From behind them Harry called breathlessly, ‘You’re more right than wrong. You can thank Michael Poole Bazalget for that, and those Arctic methane deposits he stabilised. A while later, once suitable methanotropic bugs had been bred, we were able to turn what might have been greenhouse gases into food. And then—’

  ‘We don’t farm here,’ Marsden said with some disgust. ‘What do you think we are, barbarians? We do have food machines. But as far as possible we do live off the land, so to speak. That old solar sail provides enough power for living purposes. A few metres of comet ice in the shell, strengthened against the spin stress, is enough for radiation shielding – even when we approached Jupiter. All for free, you’ll note; all we need is a little input of repair mass every century or so. People living off the sunlight and the resources of space . . . It’s as close to the dreams of the ancient Bernal as we’re ever likely to see.’

  Harry frowned. ‘Bernal? Was he on our payroll?’

  Marsden just snorted. Poole suspected Harry was mocking him.

  ‘Yes, we’re cranks,’ Marsden said. ‘Yes, most people see this as an eccentric way to live. But now our time has come, hasn’t it? We’ll be safe in here, living quietly and silently, while your star-hot GUTships are hunted down by the thing you call the sycamore seed, and the quagma-phantom infestation, and whatever in Lethe else seeks to come through those wormholes of yours. You’ll see. Even your group leader, Dr Berg, agrees with me – and agrees about what must be done.’

  Poole was surprised by that last remark. But as it turned out, when Poole finally met Miriam inside one of those bamboo huts somewhere near the equator of the craft, Marsden was right.

  Here at the equator, the region of maximum spin gravity, the load was up to about seventy-five per cent of Earth’s. Poole, who had been in zero gravity for some days, felt it in his bones. Harry, too, was evidently glad to slump down on one of the couches that littered the dirt floor.

  Dirt floor, yes: Poole found himself inside a kind of tepee, constructed of long bamboo shoots interwoven with reeds. Marsden had dumped them in here and gone in search of Miriam.

  Poole knew that bamboo cane was a popular choice of construction material in closed-loop habitats like this, fast-growing, sturdy and straight – and it served as a neat reservoir of carbon to act as a buffer for the ecological cycles. A doorway faced one of the window light-pools, so a glow like late afternoon sunlight was cast into the hut, and a gentle breeze washed in, feeling pleasantly cool to Poole, who had been brought up in Britain’s temperate climate. Good, unobtrusive environment control, he thought. This tepee was actually pretty big compared to the others around it. Poole had learned that it was generally used as a kind of town hall. But today the floor was crowded with rows of sleeping bags and heaps of blankets – many of them Poole Industries issue – and with small piles of spare clothing, first aid packs, a water bottle or two. Evidently this place was already serving as a dormitory for some of the incoming evacuees from Io.

  They didn’t have to wait long before Miriam Berg showed up, carrying a tray. She handed out clay mugs of what tasted to Poole like coffee, but probably wasn’t.

  Then she got down to business.

  ‘Well, here we are. Most everybody in this habitat is out working on fixing up the life support to cope with the new arrivals: almost a hundred of us, in addition to the hundred residents already here. Double the numbers. They have made us refugees very welcome, by the way. Though you can see that even housing is an issue.’ She smiled. ‘We’re quite a mixed crowd, Michael. I don’t know how many you met before. Aside from the Io crew there are ice-moon miners, and Oversight biologists who were there to make sure those miners didn’t disturb the native bugs in the roof oceans, and ore miners from Valhalla on Callisto, and admin staff from Daraville – even a few stranded tourists, unlucky for them. Here we are all mixed up together.

  ‘But what’s to become of us is way out of our hands. The discussions have gone up through Shamiso Emry’s Oversight committee and other bodies to the World Senate, and they have already decided to evacuate the Jovian system altogether until the emergency is over.’

  Nicola sniffed. ‘If it ever is.’

  ‘So we’re to be taken back to Earth. The trouble is, because of these quagma phantoms of yours, Michael, the GUTships are unreliable for the foreseeable future, and nobody knows if fusion drives, for instance, are going to stay safe. So we can’t be moved on; we’re stuck here.’

  Poole said, ‘Highsmith Marsden has already suggested keeping you here longer. Or some of you. Enough to maintain a breeding population, he says.’

  Miriam looked at him over her coffee. ‘He’s gone further, actually. He wants to nudge Gallia out of its transit orbit back to the inner System and relocate it to the Trojans, out here in Jupiter’s orbit. So we’d stay there permanently. Stealthed, you see. As long as we do it before your visitors notice . . . I think I agree with him.’

  Nicola had followed the exchange between them with interest. ‘Speaking of breeding populations. You two, Berg and Poole. You’re together, right? Or were. Or you will be. I can tell. Trust me, I’m good with people.’

  Miriam looked as if she wanted to punch her.

  Harry just laughed.

  ‘It’s not a big deal,’ Poole said quickly. ‘We were partners in our teens. After that – well, we got counselled out of doing anything hasty.’

  ‘Counselled? Ah. So you’re AS-platonic . . .’

  Poole remembered the therapy sessions when he had begun his own AS treatment, vividly and with some embarrassment. With AS treatment you could look forward to whole extra lifetimes – and, as the mayfly centuries ticked by and people refused to die, that was slowly changing everything about human society, from political power structures to the economics of inheritance to interpersonal relationships.


  ‘Marry young,’ Harry himself had advised his son at the time, ‘and you’ll divorce what feels like younger.’

  ‘How would you know? You aren’t so old yourself, not yet. You and my mother “married young”. And she died young. If you hadn’t come together when you did—’

  ‘Save it,’ Harry had said evenly. ‘Save her. Miriam. Save her until you’re both ready, and sure. But be aware that it will almost certainly end someday anyhow. Live long enough and you outlive anything, even your own younger self . . .’

  Poole had always felt uncomfortable with such advice. Could you really plan a relationship – could you timetable love? Looking at Miriam now, competent, strong, but somehow defensive – they had both changed so much, even before this intrusion of alien mystery into their lives – he wondered if they had already missed some elusive chance.

  ‘“AS-platonic.” I don’t like being labelled,’ Miriam said now, coldly, to Nicola.

  ‘I’m right, though, aren’t I? One reason why I never had AS treatment myself.’

  Miriam stared at her. ‘Seriously? Your mother must have offered to pay for it. Why would you turn it down? I mean, the medical benefits alone—’

  Nicola shrugged. ‘Has AS made you happy?’

  ‘Well—’

  Poole was relieved when Highsmith Marsden came bustling in. ‘I could hear you gossiping from across the habitat. What are you, children?’

  Nicola grinned. ‘So to business.’

  Harry stood. ‘Professor Marsden, I—’

  Marsden ignored him. ‘Shall we get to the point? Which is to assure the survival of mankind in the face of alien threat.’

  Harry blew out his cheeks, and sat down again. ‘You think big, don’t you?’

  Poole frowned. ‘We don’t know if there is a threat, let alone an intentional one.’

  Marsden said heavily, ‘So claims the man whose own GUTship is already a drifting hulk. And whose closest friend was the first human to die. William Dzik, yes? I follow the news too. I say we need to act fast, while we have the chance.’

  ‘Hence this idea of a breeding population?’

  ‘A couple of hundred should be enough. I took a quick look over your crews’ genetic records—’

  Harry scowled. ‘How in Lethe did you get those?’

  Marsden ignored him again. ‘Purely by chance we have a good sample of genetic diversity on board right now. The present two hundred will do the job, with a little planned breeding.’

  Nicola grinned, evidently enjoying this hugely. ‘“Planned breeding”?’

  ‘In an emergency it’s essential to act quickly. It’s rather like the efforts to save endangered species during the late days of the Anthropocene. To have even just one reserve population, one viable breeding set, tucked away here in Gallia, which can run as silently as we like – externally we’re just a ball of comet rock with a derelict-looking sail and a slightly odd heat signature . . .’

  ‘He convinced me,’ Miriam said. ‘Maybe that surprises you, Michael. Might strike you as paranoid, even. But whatever we’re dealing with here is very strange, and totally unanticipated. I mean, it named you, Michael. Or that mercury-drop Ghost thing did. You of all people should have an open mind about what comes next.

  ‘And after all, we are bottled up in the Solar System. All of humanity. A determined enough attack, from an advanced enough technology . . . I think the Professor’s right. We have to plan for the worst case.’

  Poole frowned. ‘Which is?’

  Marsden glared at him. ‘“Which is?” “Which is?” What kind of a question is that? Have you no vision at all, man? And they built you a statue at the centre of the Galaxy, did they? What does it have you doing, looking for your own arse by supernova light?’

  Harry barked laughter.

  Nicola seemed to marvel. ‘I love this guy.’

  Marsden growled, ‘Extinction. That’s the worst case. Do you kiddies need to look that word up? As Miriam implied, right now a sufficiently determined adversary could destroy us all – all extant humans. Then it’s not just our own potential deaths we are dealing with, but the deaths – or rather the non-existence – of our children and grandchildren, and off into the future. And the loss of whatever humanity might have gone on to achieve.’

  Nicola said dryly, ‘Such as statues at the centre of the Galaxy.’

  ‘Shut up,’ Poole said.

  Miriam said, ‘It might not happen. But, then, it might. And until – I don’t know, Lethe, until that sycamore seed thing speaks to us and tells it what it intends to do, we can’t even assess the probabilities. Hence, yes, I agree with the Professor.’

  Harry snorted. ‘You agree with a totally paranoid analysis. Fine, Miriam, Professor. You hide away here while the rest of us go experience the wonder of the age. An extraterrestrial visitor to the Solar System . . .! We’ll have to figure out if you’re still on company time, Miriam.’

  That made Nicola laugh. ‘Harry, I don’t like you. But I do admire your black heart.’

  ‘Professor, that doesn’t mean I’m not grateful to you for taking in my staff in extremis the way you have—’

  ‘Oh, I’m sanguine about that,’ Marsden said breezily. ‘But what I won’t allow is any alien technology aboard this station. You must deal with that yourselves.’

  Poole felt his face grow cool, as if the blood had drained from his skin. ‘You mean the amulet.’

  ‘I think it’s time you went to face that mystery – don’t you? But not in my habitat . . .’

  ‘I agree,’ Poole said.

  Nicola looked at him. ‘Where, then?’

  ‘It’s Poole family business. Evidently – it did name me. So I’m going home. I’ll take that Lethe-spawned amulet with me, see if anybody there can help figure it out. You don’t know us, Nicola. We’re a family of conspiracy theories and secrets, most of which nobody’s trusted me enough to know about, yet. Well, here’s another spooky mystery. Then I’ll decide what to do next.’

  9

  Poole’s GUTship, Hermit Crab, was hastily refurbished at a base on Himalia.

  This small moon followed a moderately eccentric path ten times the width of the orbit of Ganymede. The facilities were modest, even compared to the sparsely inhabited communities elsewhere in the Jovian system: just a handful of airtight shacks buried in loose, impact-shattered ice. But this irregular lump of rock had in fact been humanity’s first cautious footfall in the Jovian system, one of the Recovery-age space projects back in the twenty-fifth century. And now, it was believed, Himalia ought to be safely beyond the reach of the swarming quagma phantoms, which seemed to have stuck mostly to the inner regions of the Jovian magnetosphere and the big human settlements there, no doubt in search of the high-energy-density sustenance they craved.

  These days the small maintenance facility on Himalia was owned and operated by Poole Industries, though much of its work was under licence to various UN agencies and fulfilled by subcontractors. So the battered Hermit Crab, towed out here by fusion-powered tugs, was bumped to the head of a line of similarly afflicted hulks, and its GUTengine core, infected by quagma phantoms, dumped and replaced. The work was done in a couple of days.

  Poole fretted over this; he always felt guilty when his position in the family company earned him what felt like privileges.

  Nicola, who spent the wait mostly in a low-gravity sauna, just laughed at him. ‘You’re a Poole. You’re supposed to have had your conscience extracted at birth. Just like we ejected that polluted drive system. Whoosh! Gone.’

  ‘I didn’t ask for any of this. I’d much rather be building my wormholes. And staying at the back of the line.’

  ‘Well, tough luck. Isn’t that what your father would say?’

  ‘Maybe. What’s more to the point is what my mother will say.’

  Nicola stared at him. The
n, with an evident and uncharacteristic effort at tact, she said, ‘I thought your mother died.’

  ‘It’s complicated. Let’s get out of here.’

  It took six days for the Hermit Crab to drive herself across the Solar System from Jupiter to Earth, the GUTdrive burning all the way to deliver a solid one gravity’s thrust: three days’ acceleration to the turnaround, and then three more days of deceleration. Her peak speed was a little less than one per cent the speed of light, and throughout the journey she would be visible as a brilliant shifting star across the inner System.

  There you had the paradox of GUT technology, Poole thought. The drive was, if anything, overpowered for interplanetary travel; a GUTship was capable of interstellar missions, journeys tens of thousands of times longer than this intraSystem hop – and, though a GUTdrive could never exceed lightspeed, it could get so close to that limit that time dilation would compress the subjective duration of such journeys into easily survivable periods. But within the Solar System, a GUTship was enormously expensive in terms of reaction mass, all for a cargo capacity of no more than a few hundred tonnes. Which was where Poole’s own wormhole network was supposed to come in. Once built, it would enable the transfer of high-volume cargoes much more rapidly, and the economy of the Solar System would be transformed – although in fact it was the technology itself that attracted Poole’s interest, not long-term theoretical implications he might never live to see.

  If, he thought gloomily, the project wasn’t abandoned altogether after this string of catastrophes attached to a mere prototype. The immediate future seemed galling. Young he might be but he’d already had to fight hard, alongside his father, to get this far – especially on an Earth which had just endured an age of recovery and cautious rebuilding, beginning with Michael Poole Bazalget’s Bottleneck-era Stewardship movements. And now all this alien strangeness had thrown his plans into chaos.