Xeelee: Vengeance

by Stephen Baxter

  ‘Yes,’ Poole said sourly. ‘And like Harry says, you’re Loki, the trickster.’

  ‘Wrong mythology.’

  ‘Whatever. Come on, let’s get back to Grantt, we don’t want him getting more suspicious of us than he already is . . .’

  And while the days of the journey went by, as they explored and speculated and schemed, the Cache grew in their field of view, from a grain of light, like a single pixel blinking in a faulty screen, to a discernible solid form.

  To an artefact.

  27

  They came down on the Cache from above the ecliptic, the plane of Mars’s orbit.

  The Cache itself was an enormous box, tipped towards them.

  From a distance it looked featureless, Poole thought, pale grey-white, shining softly as if from some inner power source. But telescopic images proved that its surface in fact bore slight imperfections. There were splashes of debris from random collisions with natural objects, the dust and rocks and asteroid fragments with which the Solar System was littered: impacts which had left behind rubble, but seemed not to have harmed the Cache itself. And there were those dimples: some kind of intrinsic marking, it seemed, scar-like discolorations, roughly circular, perhaps a hundred metres wide, one on each of the six faces. A new feature since the Cache’s emergence from the Sun.

  All this was surrounded by a loose cloud of sparks in the night: ships and drones from Earth, Mars and elsewhere, some of which had accompanied this thing from the Sun. None approached close.

  Soon the Bellona had passed through the horde of monitors, and drew closer than any other crewed vessel so far.

  And as they approached, the Cache grew until it filled the frame of the lifedome viewing windows, and then further, until its edges were lost beyond the perimeter of Poole’s field of view, and the upper surface opened out like a landscape.

  When they had still been far out, Poole didn’t seem to have found it difficult to accept all this. He was used to big artefacts in space, after all; he had grown up among them; he had built his own two-hundred-metres-wide tetrahedral wormhole portals in the Jovian system. But this giant spanned a thousand kilometres, larger than some moons, and now it was so close it was too big even to see properly. It presented a clash of categories – the huge scale of natural objects overlapping with the engineered precision of artifice – that disturbed him on some deep level.

  Nicola said, ‘We’re being nagged for comments. Lots of public interest in you, Michael.’

  ‘What in Lethe am I supposed to say?’

  Grantt murmured, ‘Just tell them what you see.’

  ‘Well – it’s kept the same shape. Ever since the Xeelee dug it up out of Mercury . . .’ The Xeelee: they had shared that enigmatic family-archive name with Grantt days ago; Poole was confident any such lapses would be filtered out before his message was shared more widely. ‘It’s still a cube.’

  ‘Precise to the limits of our measurements, yes.’ Grantt checked a record. ‘We can’t see through that hull. Even neutrino probes don’t work. But we do have some data on the internal mass distribution from the deflection of flyby probes. Although the overall mass hasn’t increased significantly since it left the Sun, the internal structure has changed. You have an outer shell, very thin, of the sun-catcher material they’re calling hull plate. Inside the box appears to be some kind of gas, with a big dense mass at the centre – an object the size of a respectable asteroid. And other objects moving around in there, in swarms. There’s speculation that they are like the objects that tailed the Xeelee out of your wormhole, Michael, what you called raindrops. A lot more of them, though. Meanwhile, from a pilot’s point of view, those are nice flat surfaces to land on.’

  Poole was startled. ‘Land on?’

  Nicola looked electrified, as Poole might have predicted. But she recovered quickly. ‘At last, we learn about the mission plan. So secretive, you Martians.’

  Poole shot her a warning glance.

  Grantt nodded. ‘It’s the logical next step. And the mission designers have prepared. We won’t take the Bellona down, obviously. We have flitters. Hopefully the artefact’s gravity will be enough to hold on to a landed ship, and we have adhesive pads that might work on that surface. The labs in Kahra produced prototypes.’

  Nicola smiled. ‘Or if the worst came to the worst, I guess we could use thrusters to hold us down. Just a gentle, continuous firing downwards.’

  Grantt turned in his couch and faced her. ‘Hold us down, Nicola. Me and Michael. Not you.’

  ‘What are you talking about?’

  ‘About mission rules. Set out by the Kahra government. Look, you lived on Mars for months; you know our culture is shaped by adaptation to a basically lethal environment. We take our safety rules seriously. And as commander of the mission and representative of the government that sponsored it—’

  Nicola’s expression was blade-hard. ‘You’re leaving me behind.’

  Grantt continued calmly, ‘Two land. One stays in the Bellona, at a safe distance, maintaining the integrity of the mother ship, ensuring comms links between the landing party and the monitoring fleet and Kahra, and providing abort options. Basic protocol. It’s an essential part of team operations in a situation like this.’

  Nicola, angry, disappointed, snapped back, ‘To Lethe with the team. Why me? I’m younger than you, and smarter than him. And I’m more disposable.’

  That forced a laugh from Grantt. ‘I admire your honesty. But it was made plain to me before we launched that Michael and I would be the landing party. Michael because, well, he’s Michael Poole.’ He looked at Poole quizzically. ‘I haven’t been briefed on it all. Interplanetary politics, even family friendships, don’t yet allow that. But all of mankind knows you’re somehow central to all this, Michael.’

  ‘I wish I wasn’t,’ Poole said.

  ‘Liar,’ Nicola muttered.

  ‘And me because I represent Mars. They gave me flags to take down.’

  She sounded disgusted. ‘You’re like some tin-pot Anthropocene hero.’

  Grant grinned, almost shyly. ‘Childhood dreams.’

  Poole asked, ‘And why didn’t you share this plan with us before?’

  ‘What, and jeopardise our carefully wrought team harmony? She’d have thrown me off the ship. Or you. Now, do we have a problem with this? Shall we abort? Because, incidentally, the same rules forbid me going down there alone, in case my crew mutinies.’

  Poole touched Nicola’s arm. ‘Look, whatever the outcome today, I don’t think this is the end of the drama. You’ll get your chance.’

  A moment of silence between the three of them, while the Cache loomed ever closer, a plain of light spreading further – and with some detail visible to the naked eye now, Poole saw: a pale lake of discoloration, a scattering of sparkling ice, or dirt.

  Grudgingly Nicola said, ‘You have a point. Let’s do this.’

  28

  So Poole, for once, took the left-hand pilot’s seat. Without further comment, for sake of disturbing the crew’s uneasy truce, Grantt strapped in to his right.

  The flitter was attached to brackets under the lifedome. Looking up through big blister windows Poole could see the lifedome’s base, a flat surface studded with cabling, sensors, ducts. To his right the ship’s spine, a complex pillar of engineering.

  And below him a shining plain. It was no longer possible to think of the Cache as an artefact. It was as if he was suspended over some calm sea into which he was about to plunge. He looked away and got on with his work.

  With the grudging co-operation of Nicola, stranded up in the lifedome, Poole ran through system checks. If the Bellona was a covert warship, Poole saw no signs of weaponisation about the flitter. In fact there seemed to have been additional safety features incorporated into the flitter’s standard systems.

  He remarked on this to Grantt. ‘I kn
ow we mustn’t look hostile, and I guess we don’t want the thing accidentally blowing up, in these circumstances. But I’m afraid that if I sneeze the main drive will shut down.’

  Grantt laughed. ‘Then don’t sneeze.’ Going through his own checklist of backup checks, he sounded uneasy, even tense. Poole saw through the man’s faceplate that he was sweating heavily.

  Poole tongued a switch and spoke privately to Nicola. ‘Jack’s kind of on edge.’

  ‘I wouldn’t have been.’

  ‘Too late for that. You think I should say something to calm him down?’

  She laughed softly. ‘Michael, you may have the Poole genius genes from your mother, but you’ve got your father’s tact. Keep it zipped. Ready for launch, by the way. In five, four, three . . .’

  The descent seemed agonisingly slow.

  That near-featureless surface expanded below him, the distance to its milky uniformity continually fooling Poole’s eye. But the instruments worked; whatever this Cache was made of, it was material, and returned echoes to sensors ranging from radar to neutrino pulses.

  ‘One kilometre up,’ Grantt called. ‘Nine hundred metres. Eight. Is this helping?’

  ‘Keeps me awake as the flitter flies itself down.’

  ‘I suppose you’re used to this. The cautious pace of big engineering projects in space, huge masses drifting in close proximity. Six hundred. But, don’t you feel self-conscious? You get the sense that everybody who’s awake in the System is following us. I guess you’re used to that too.’

  Poole shrugged. ‘Not so much. I mean, not before the Xeelee incursion. Unless we do something spectacular – like the first time my father and I flew through a test wormhole – most of our scrutiny is from the specialist technical press, or from our investors, or the various Oversight boards.’

  ‘But you’re a Poole. You were a famous baby.’

  Poole winced. ‘My father shielded me from that, at least.’

  ‘Coming down nice and easy. Four hundred.’

  ‘You’re right, though,’ Poole said. ‘A routine docking wouldn’t be taken much faster. Of course this isn’t a regular docking.’

  ‘Three hundred. Bellona, you know, has anti-impact safeguards. Some kind of laser shield to destroy any interplanetary debris in its way. Two hundred. I wonder if the Cache has similar defences.’

  ‘Well, there’s already debris down there, on the surface. It doesn’t seem to care about minor impacts. I don’t know what would happen if we threw Ceres at it—’

  ‘One hundred. Nice and easy.’

  ‘But evidently smaller objects are no threat. And we’re moving slower than any space rock. We’ve done all we can to appear harmless.’ He touched a softscreen control. ‘Slower still, now.’

  Grantt shut up, at last.

  The view expanded further, and the closer they got the more lost Poole felt. He found himself searching for detail, a scrap of that meteorite debris, anything, to give himself a visual anchor. But they’d deliberately picked out a clear area of the hull to approach, and now he was so close there was nothing to be seen, no detail. A descent into abstraction.

  The landing was feather-light.

  They just sat still, for five seconds, ten, allowing the systems to settle.

  Then Poole glanced over at Grantt. ‘OK. We rebounded slightly, from the give in the flitter’s undercarriage. That surface is hard as basalt. Harder. And that one per cent gravity is holding us down, for now. Trying the adhesive clamps.’ He touched a control.

  The flitter shuddered softly.

  Poole checked his instruments. ‘Seems to be holding. The flitter’s not going anywhere soon. Time for the footprints and flags, Jack.’

  Grantt grinned. ‘It’s my home world we came from. You don’t mind if I . . .’

  Poole shrugged. ‘Be my guest.’

  They both crowded into the flitter’s airlock. They closed up their suits, and, at Grantt’s insistence, checked them over with a care Poole hadn’t been subjected to since training school.

  Then, at last, Poole slapped a control to open the hatch.

  A milk-white plain.

  The sun was low over a geometrically precise horizon, and the flitter’s landing gear cast long shadows. The sky looked black to Poole’s light-adapted eye, but he saw a bright spark that must be Mars, and others sliding across the dome of the sky: ships, points of fusion light or GUTdrive radiation glaring in the dark.

  Trailing a safety umbilical attached to the flitter, and moving with care in the virtual absence of gravity, Grantt drifted down a couple of ladder rungs. And he set foot deliberately on the Cache’s hull. ‘A human footstep on an alien ship,’ he said softly. ‘Nothing like this has happened in our history. Let’s hope this is the start of a peaceful and productive encounter.’

  Nicola growled in Poole’s ear. ‘Should’ve been me.’

  ‘Hush. He’s talking to the Solar System. And his grandchildren.’

  Grantt took one step, two, drifting up into the vacuum each time, falling back like a snowflake, trailing his umbilical. ‘Nothing seems strange,’ he reported. ‘Or at least, unexpected. I can sense the gravity, just, a definite up-down sensation. The view is – stark. Testing my boots.’ More adhesive grippers had been fixed to the soles of their boots; now Grantt tapped a control on his suit’s right leg, and took more steps, one, two, out of the flitter’s shadow and into the Sun’s glare. ‘Walking feels kind of sticky . . . OK, Michael, come on out.’

  Poole slid out of the flitter’s hatch easily, letting himself fall, checking his umbilical didn’t snag. He took a few steps, joining Grantt. ‘Sticky, yes. I trained with magnetic-grip boots once; it feels like that.’

  Grantt opened a small compartment on the side of the flitter. He drew out two slim flagpoles that telescoped open, and two flags that he draped over fold-out bars. One flag was the ancient UN standard, pale blue, the laurel wreath cradling a schematic Earth, the other the defiant red of a canal-strewn Mars, symbol of ancient fantasies and future dreams.

  Then, as they had hastily discussed in advance, Grantt and Poole stood side by side, checking they were in full view of the flitter’s cameras. ‘Here,’ Grantt said softly, ‘the children of two human worlds first set foot on a craft from beyond the stars. We came in peace for all mankind.’ And, awkwardly, evidently self-consciously, he saluted the flags.

  Poole, still more embarrassed, followed his lead.

  Nicola chuckled in his ear. Poole ignored her.

  With some relief, Grantt rubbed his gloved hands and turned to Poole. ‘So that’s over. Let’s get on with it.’

  The flitter’s exterior cargo hold was packed with instruments: beacons, sensors both fixed and mobile. They quickly unloaded the gear.

  As Grantt set up the science stuff around the flitter’s landing site, Poole opened another hatch which, as Grantt had informed him on the way down, contained a surface vehicle. It was just a frame, a couple of bucket seats, a small GUTengine motor, and big balloon tyres fitted with the same kind of adhesive pads that had been applied to their boots and the ship’s clamps. All this had evidently been adapted from lunar and Martian technology, centuries old and supremely robust. It was a trivial task for Poole to unfold the frame and set it up – indeed, the vehicle was smart enough to do most of it for itself.

  Everything on the mission had backups, Poole realised, including, for the rover’s passengers, a couple of jet packs. If they couldn’t drive back to the flitter in this thing they could, cautiously, fly home . . . Or indeed the flitter, piloting autonomously or controlled by Nicola in the Bellona, could come and get them. And if all else failed, Nicola could fly down in the GUTship itself and make some kind of pick-up. Multiple abort options.

  Grantt spoke as he worked, for the benefit of the watching overseers as much as Poole, or himself. ‘We’ll be leaving much of this gear in place w
hen we depart. I doubt frankly that we’ll learn much that we haven’t already discovered from remote sensing, but in science you never know until you get in there and measure something . . .’

  Poole was an engineer. A tinkerer. Half his mind, almost, was engaged in the pleasurable chore of checking out the surface rover. The other half, almost, listened to Grantt’s distracting patter.

  But that left a little of his mind to be distracted by the view.

  Under low sunlight, he was standing on a plain, flat and all but featureless, that stretched far away. He was in vacuum, so there was no mist to give a sense of distance – and he knew that there was no curvature as on a planet, so no horizon. He was close to the centre of a vast square plate, a full thousand kilometres across – he was a flea on a vast packing case – and in theory he should be able to see all the way to the edges, even to the corners. Yet he could make out nothing of the edges. And the human clutter that they were spreading out around the flyer, bright in the sunlight, seemed a gross intrusion, out of place against this clean geometry . . .

  Nothing but a plain, an abstraction, that cut the universe in two: above and below . . .

  An infinity that drew his gaze . . .

  A figure stood in front of him, a face dimly glimpsed behind a plate filtered for sunlight protection. ‘You OK, buddy?’

  For one second Poole didn’t know who this was. ‘Jack. Yes.’

  ‘You weren’t here for a moment.’

  ‘I’m sorry. I—’

  ‘Don’t sweat it. We’re talking through a direct link, OK? Nobody can hear, just us for now. It’s the perspectives, right? It is kind of hypnotic.’