Xeelee: Vengeance

by Stephen Baxter

  ‘Then a moment of what looked like an upward hail – molten, red-hot rock droplets, I imagine, washing back up the tunnel of vacuum left by the passage of the Probe. Molten rock, and perhaps superheated vapour. Mars’s permafrost layer flashed to steam.

  ‘Then, a pulse of heat crossed Lockyerville. It was a wave of compressed, superheated air, washing out from the impact site. I saw detonations among the domes and shelters of the town: anything, I suppose, that contained oxygen to feed fire exploded and flashed into fragments. The very surface of the glass roads melted.

  ‘Then a tremendous ripple of energy washed out through the ground, at supersonic speeds, a circular shock wave travelling out through the landscape itself, tracking the air shock. I could see it. It overwhelmed the material strength of the rock itself, pulverised the upper ground, shattered bedrock. This wave travelled kilometres before stalling, with a great mound of overturned strata heaping up to form the rim of a new crater. And I saw a kind of rebound too, a reflected wave that smashed back to the centre, the point of impact, to throw up a rough-edged mountain there. Thus, a new crater.

  ‘All these events happened in mere seconds, you understand. The mechanism is well understood. At the point of impact, the tremendous kinetic energy of the Probe had hammered down on the bedrock beneath, compressing, vaporising it. That caused a tremendous subsurface rebound: a secondary explosion.

  ‘But even after this monstrous beginning, even as rock fragments begin to hail back down to the ground, a wave of destruction washes out from the epicentre through the atmosphere: a great circular storm already kilometres across, of wind and heat and red Martian dust, driven by the impact heat, an obliterating wave travelling at the speed of sound. It will be spectacular when this reaches the arcologies at the rim of Hellas.’

  ‘Later.

  ‘I am high, now, obeying the cautious flitter’s safety mandates. So high I can see the curve of the world. I feel as if I am halfway to orbit.

  ‘And I can see the impact region, clearly. A new crater at the centre of Hellas, perhaps six kilometres across. It is sharply defined. So new, so perfect in its symmetry, that it is almost beautiful. Innocent.

  ‘Lockyerville is entirely gone, of course. Not even the graves remain. Beyond that, the landscape has been scraped clean of human traces across perhaps twenty kilometres. Nothing is left of those who lived here for generations, or any of their works.

  ‘And the damage to the terrain of Mars itself, and the organisms I study, is extensive, across perhaps two hundred kilometres.

  ‘Above me the sky is darkened by a plume of ejecta hurled up into the atmosphere. There will be cooling, across this small planet.

  ‘What savagery! An impact that was felt in seismic echoes right around Mars. And deliberately aimed. Those who directed this thing must have understood that there were living creatures in the impact zone. I think now of the similar packets of destruction heading for the Moon, and Earth. I wonder what will come of this day.

  ‘Yet, I reflect.

  ‘I reflect that for all this barbarous destruction, Hellas is an impact crater ten times wider than this new blister of damage at its centre. Even the Xeelee hasn’t matched that act of nature. Not yet, anyhow.

  ‘I reflect that for all the harm it inflicted, perhaps this ugly weapon really was a probe, as much as a tool of destruction. Michael Poole tells me that some fine-grained observing instruments have seen what appear to be flecks of debris rising up from the impact, riding the thermal currents from the disaster site, even rising to the top of the thin air, reaching space. Chips of carbon, it is reported. Perhaps, somehow, this object is even now reporting back to its maker: about the planet it encountered, about the nature of those who inhabit it.

  ‘And as a biologist I reflect that the great pulse of heat delivered by that impact must have melted the permafrost layer that lies deep beneath the Martian soil. A warmth that can linger for a thousand years. We know there are organisms on Mars adapted to take advantage of such “impact summers”. If the Xeelee’s intention was to inflict death, for whatever motive, it is somehow a comfort that on one scale at least it may, inadvertently, have given life.

  ‘But it’s a small comfort. I am a Martian. Now Martians have died, through the actions of the Xeelee – and there can be, now, no question about its intent. I look back at my own naïve reactions to my exploration of the Cache – which has turned out to be a weapons platform – with shame. How could I have been so foolish? Well, no more.

  ‘All that for tomorrow. Now, I, like the rest of mankind, turn to the problem of how we are to deal with this proven destructive presence amid our worlds, the Xeelee.

  ‘And how we are to deal with the objects heading for Earth and Moon.’

  36

  Six hours after the Hellas impact, Poole and Nicola pulled the Hermit Crab out of its dry dock in Martian orbit. At two gravities thrust, they raced to intercept the second and third Probes, which were still following their direct route from the Martian L5 point to Earth and Moon.

  They overtook the Probes two days out from their presumed targets.

  Poole settled the Crab into a trajectory parallel to the course of the Earth-bound Probe, less than ten kilometres from that milk-white hull plate shell. Just as with the Mars device, they found themselves once more in a crowd of craft, most of them uncrewed, some of which had been trailing the Probes ever since they had left the Cache at the Martian L5 point. Some of the ships splashed light on the Probe, but its seamless hull merely reflected a diffuse, featureless glow.

  In the further distance, visible only telescopically, the Moon-bound Probe raced along its own path.

  ‘It looks unreal,’ Nicola said, munching a nutrient bar for breakfast, staring at the Earth Probe. ‘Like a dragon’s egg.’

  ‘More old mythology?’

  ‘Isn’t that appropriate? We’re facing the Xeelee as Beowulf faced Grendel’s mother, armed only with an iron sword, and with about as much comprehension. Yet he fought her in the end, and won. Although eventually a dragon killed him.’

  ‘Whereas when the Mariner from Mars took on the King of the Sand People, he lost, first time.’

  Nicola smiled. ‘Just goes to show, when you go to war you have to choose the right legend.’

  ‘You think this is a war now?’

  She glanced out at the Probe, bathed in light. ‘Don’t you? We should take on this Lethe-spawned thing. Hit it with all we’ve got. Us and this ragtag navy around us. I’m talking windows of opportunity, Michael. If we manage to destroy this thing, fine—’

  ‘That seems doubtful. Have you seen the latest reports from Hellas? Came in while you slept. There are indications that the Mars Probe survived after all. Mass surveys of the crash site have detected it, buried in the smashed bedrock. The damage to the planet was inflicted by the kinetic energy the Probe shed on impact, but it is still down there. That hull plate is tough stuff. Whatever we try we may not be able to destroy the Earth Probe—’

  ‘At least shove it aside, then. And the sooner we try that the better. It’s like asteroid deflection, Michael. Spaceguard. If your killer rock is far enough out, a slight deflection can cause it to miss its target by thousands of kilometres . . .’

  ‘Any such attempts are vetoed for now.’

  This was Harry’s voice. His disembodied head sparkled into Virtual existence in the middle of the lifedome. Naturally, Poole noticed, the head was a significant fraction larger than life-size, the head of a heroic statue. That was Harry for you.

  ‘Hmm. An immediate response to my remark,’ Nicola commented. ‘We’re still light-minutes out from Earth. Are you another Virtual copy, Harry?’

  ‘It seemed only polite, rather than keep you waiting for replies. Usual caveats apply; I am a top-quality authorised representation of Harry Poole. But don’t take anything I say seriously until I’ve had time to sync back to my o
riginal, on Earth.’

  Poole grinned. ‘Harry, I never take you seriously anyhow.’

  ‘Tell me about it. Just to reiterate, from what I overheard of your conversation: any hostile action against the Probes, either of them, is still forbidden. Even active sensors are ruled out. Not so much as a ping with a single neutrino. Even those floodlights are controversial. I do take your Spaceguard logic, Nicola; if all we can do is deflect these things, the sooner we try it the better. But—’

  ‘But you’re not going to try at all.’

  Harry sighed. ‘You kids understand so little. You know so little. There is no “you”, to “try” or otherwise. It’s not as simple as that.

  ‘You’re dealing with the democratically elected government of a more or less united planet – a planet in danger, and with its neighbour the Moon under similar threat, or a greater threat, actually, in proportion to the Moon’s size and population – and with the background of the disaster that’s already hit Mars, and the complication of the consequent relief effort we have had to mount there.

  ‘Plus you have such difficulties as the AS lobby: the struldbrugs, always slow to come to a decision, slow to react. And the activists, groups like Paradoxa who, having cut their teeth on learning how to manage the long-term implications of climate adjustment, now think they’re ready to deal with the alien. You want to know more about that, ask your mother, Michael.

  ‘And then there’s the public mood. Which is of growing anger, as you’d expect. Why hasn’t somebody done something yet? Why was this allowed to happen? And so on. A lot of this is remote-link chatter, but I think we’ve all been surprised to see how people have been prepared to show up in a mass, like this was still the early Anthropocene. In person, I mean. I’m talking about mobs. The Federal Police had to contain a noisy demonstration outside the UN headquarters in New Geneva. Look – I’m trying to tell you that there’s no simple entity to handle the situation, no clear decision-making process. It’s more as if we’re waiting for a strategy to emerge from a planet-wide conversation.’

  Nicola said, ‘And so everybody sits around gassing while this weapon falls from the sky. You know, we don’t need a bunch of Virtuals and old folk in charge right now. We need Beowulf.’

  Harry frowned. ‘Who? . . . Looking it up. Oh. Iron Age-type warlord. Well, maybe, Nicola, or maybe not. We aren’t that kind of society any more, where almost everybody died before they grew old, and the leaders were testosterone-pumped young men dreaming of nothing but glory in the afterlife for themselves, and wealth and power for their kids. The irony is, of course, that if we had stayed that way we probably wouldn’t even be here, as targets for the Xeelee’s diamond bombs.’ The inflated head sighed hugely, its every motion magnified almost to comic effect.

  ‘All this philosophising, even as the knock-out blow is heading for Earth–Moon.’

  ‘I didn’t say I agreed with it,’ Harry said grimly. ‘I’m just trying to show you the debate. But . . .’

  Poole looked up now; he hadn’t been paying full attention. ‘I know your buts, Harry. But what?’

  Harry’s floating head turned to him, and grinned. ‘Power is shifting, Michael. At the highest echelons, under the pressure of this Xeelee incursion. Even though most people don’t realise it, even those at the heart of government. Even though what they think is shifting is, not power, but blame.’

  ‘Blame?’ Poole asked. ‘Who are they blaming?’

  ‘Us. Me. The Oversight committee appointed to advise on the Xeelee incursion, all the way back to the irruption from the wormhole in the first place.’

  ‘I hate to say it,’ Nicola remarked, ’but that’s unfair. Even to you.’

  ‘Of course it is. Since when has fairness mattered in human affairs? Especially at the top. We overseers were just a bunch of industrialists and engineers and scientists and philosophers – not politicians, not soldiers, not security experts, not even police – drafted in to advise the UN agencies. We had pitiful resources, we had no executive power, we have generally been forbidden to act in any positive way for fear of upsetting the intruder. And now that Hellas has been diamond-bombed, they’re saying it’s all our fault. But, you see, at least it shows a subtle shift of attitude. It’s a small step from “Why didn’t you do something to stop that?” to “What are you going to do about the next time?”’

  Nicola grinned back. ‘And you see that shift, and you’re ready to capitalise on it. Harry Poole, I withdraw my previous insults.’

  ‘Why, thank you, Nicola. Please disregard various contemptuous sneers likewise.’

  Poole, meanwhile, was feeling increasingly uncomfortable. ‘What are you saying, Harry? That you and your buddies are mounting some kind of slow-motion coup?’

  ‘Did I say that?’

  Nicola looked at Poole. ‘Michael, somebody needs to do something. I can understand the dismay that the first alien to show up in the Solar System is this ugly bomb-lobbing anomaly, instead of your Mariner from Mars in his crystal spaceship. But we can’t just hide away in some fantasy of love and cosmic peace. We have to deal with this. We need somebody to lead us.’

  ‘Maybe, but even if that’s true – not my father. Not Harry Poole! Nicola, I’ve watched him pursue his own agenda ever since I was born.’

  ‘A little father-son rivalry is understandable, Michael.’ Harry sounded unperturbed. ‘But you have to see—’

  ‘No. I’ve seen enough.’ Poole slapped his palm on an override control.

  Harry’s Virtual head seemed to expand, and then softly detonated in a cloud of fast-dissolving pixels.

  ‘Well done,’ Nicola said sourly. ‘So because of your childhood issues you’ve cut us off from contact with the government. Very mature.’

  Poole was frustrated, angry. ‘You don’t get it. Harry doesn’t care about anybody else. All he cares about—’

  ‘You told me. But at least he seems to be trying to do something about this situation we face. What are you doing?’ She drifted closer to him, her scuffed jumpsuit loose, the remnant of her breakfast bar still in her hand. ‘Come on, Poole. You’re not facing up to this. You can rage about your father’s character flaws all you like, and your mother’s. Poor little Michael. But the truth is you are central to all this, somehow. It was your wormhole that let the Xeelee into the Solar System in the first place.’

  He had to grin. ‘You keep pushing me, don’t you?’

  ‘Somebody has to.’

  ‘You already made me go into the Sun. And made me risk my life, and Grantt’s, inside the Cache.’

  ‘Only because he wouldn’t let me come in with you.’

  Poole gestured at the monitors, which showed a drifting cloud of ships around that central, egg-like anomaly. ‘Now we’re in the middle of all this. What am I supposed to do? We’re not allowed to do anything.’

  She snorted. ‘Allowed by who? By a paralysed government? By a society that’s become so old and clogged-up by its own past that it can’t respond even to an existential threat? By a father, who, if you’re right, is trying to use all this to grab power for himself? You’re on the spot, Michael. What do you feel? Right now? Come on. Don’t think about it. Tell me.’

  He looked again at the cabin’s softscreens, at the image of the Probe, at its projected orbit which arrowed almost straight, now, towards Earth – in fact to the Atlantic, according to the latest projections. He said slowly, ‘I feel – outrage.’

  ‘And what are you going to do about it?’

  When he didn’t reply, she left the lifedome in disgust.

  37

  Twenty-four hours out from Earth – over twenty million kilometres in distance, still fifty times further out from Earth than the Moon – the Probe’s likely impact was narrowed down to a specific corner of the eastern Atlantic Ocean.

  Poole and Nicola got ready for the encounter as best they could. They took do
ses of stimulants to help them keep awake, relaxed, alert. A full day before planetfall, at Nicola’s recommendation, they donned skinsuits.

  Around the Probe itself, though, little changed. Poole monitored the activities of the improvised accompanying fleet, the drones and crewed vessels, all backing off before the Probe’s advance. Even now, hopeful, hapless efforts to contact the Probe continued. At one point, a huge Virtual of a human face was projected before the Probe, smiling wisely and mouthing words of peace and welcome.

  ‘And I thank the gods who swim in the black waters of Lethe,’ Poole said, heartfelt, ‘that that face is not my father’s.’

  None of it got any response.

  And on Earth, meanwhile, as that twenty-four-hour mark passed, the evacuations began in earnest.

  Nicola said, ‘Look at this. You can see the refugees from space.’

  She was looking at images of the North American Atlantic seaboard, the part of the continent most under threat. Under a clear sky, the Towers and other modern buildings shone like jewels against the green, and the old cities of the coast and the lowland plain were splashes of urban sprawl: Boston, New York, Philadelphia, Baltimore, Washington, saved during the age of flooding, preserved ever since, and now under threat once again. And all along the coast the western routes leading inland or to the higher ground were black with traffic, slow-moving as seen on this scale but a continuous, deliberate, dense flow. Monorail lines were continuous blurs of motion, in the air waves of craft could be seen working their way through unusually crowded skies, and here and there the spectacular fireworks of space-capable craft shot up from the ground.

  Poole said, ‘I guess you would see this all around the Atlantic coast. In South America, Europe, Africa . . .’ He checked a news feed. ‘The regional governments are already organising drops of food and other supplies into safe areas. Refugee camps.’

  She snorted. ‘Safe until what? Until the next time the Xeelee decides to take a pot-shot at the planet?’