World Engine

by Stephen Baxter

  ‘Ready for the landing approach,’ Nicola said now. ‘We’re being pinged from the base. Think they’re looking forward to seeing us, sir.’

  Lighthill spoke directly to the ground. ‘Coming down right on top of you, McLaurin Minor, you old rascal. Thought I’d surprise you before you had a chance to hide the gin bottles.’ He glanced around at his augmented crew. ‘They will make a fuss of us, you’ll see. You new bugs might get a little overwhelmed. These chaps don’t get too many visitors out here, after all . . . Prepare the access tube, Bob.’

  ‘Right-o, sir.’

  61

  For Malenfant and the others, another eerie passage through the access tube from the Harmonia down to one of those Nissen huts on the ice of Melinoe. Malenfant was aware that the Harmonia, carried a planetary lander. Evidently not thought necessary for this gentle descent.

  Almost as soon as they had all reached the surface, airlock doors were thrown open with alacrity, and a man came bustling out, in what looked like a grubby coverall, crumpled, once powder blue, perhaps. He was short, dark, squat, with a pipe protruding from beneath a worse moustache than Lighthill’s. His nose and cheeks were speckled with broken capillaries. A drinker, then, Malenfant thought.

  He walked straight to Lighthill. ‘Geoff, you bounder.’

  ‘McLaurin Minor! Good to see you haven’t blown yourself up yet.’ The two of them shadow-boxed, before embracing in a backslapping, jokey way.

  Deirdra watched this display open-mouthed.

  They passed through the hatch into an airlock chamber, while two more crew emerged from deeper within, and the space felt significantly crowded now, with ten people – ten, that was, if you counted Bartholomew, who was keeping himself to himself. There were quick introductions. Under McLaurin’s command here on Melinoe were Guy Briggs, introduced as an engineer, tall, blond-haired, elegant, with a precise moustache – dapper was the word that came to Malenfant’s mind – but thoughtful-looking. And Josh Morris, shorter, bespectacled, a little younger than the others, a little overweight perhaps. He was the principal researcher, and maybe, Malenfant wondered, he might be eschewing the rigours of low-gravity exercising for too long in his laboratory. Or the galley.

  Now McLaurin stood back from the chattering crowd and clapped his hands. ‘On behalf of HMS Melinoe Station, I formally welcome aboard Wing Commander Lighthill and his crew, and guests. I will show you to your quarters, and then we can all enjoy the rather handsome meal of welcome our chef has prepared,’ and he nodded to Josh Morris.

  There was actually a ripple of applause. Malenfant struggled not to laugh.

  Then Lighthill responded. ‘On behalf of the crew of the Harmonia, thanks very much, McLaurin Minor. And I think you’ve deserved your prize. Bob?’

  Bob Nash grinned, pulled a packet of tobacco from his inner jacket pocket, and lobbed it through a gentle low-gravity arc to McLaurin’s waiting hands.

  ‘Howzat!’ McLaurin said, beaming. ‘Thank you, Bob. Now if you will follow me . . .’

  Malenfant held back as the rest of the crew filed out through the airlock, one at a time, and into the main structure.

  When it was his turn, Malenfant, at the back of the line, found himself walking with Deirdra and Josh Morris.

  ‘So they said you’re the chef,’ Deirdra said, evidently teasing him. ‘I thought you were chief scientist.’

  ‘Well, so I am.’ He fixed his glasses with a finger-push over his fleshy nose. Malenfant thought he might actually be blushing. ‘Chief scientist, I mean – chief because I’m the only scientist, though I do rope in the others for some of the donkey work. Sample taking, equipment set-up, that sort of thing. Don’t trust them in the lab, though . . . Or in the kitchen actually.’

  They walked through another open airlock into an extended space, a half-cylinder with a low, curving roof. Evidently this was the main section of this ‘Nissen hut’. Malenfant saw ribs overhead, as if the roof structure was made of corrugated iron. They walked, or Moonwalk-hopped in the feeble gravity, along a narrow track of some kind of fabric laid out over what looked like a glass floor. Under the glass Malenfant saw dirty ice, cracked, grainy, and streaked with some kind of brown deposit.

  ‘This is my domain, in fact,’ Josh said. ‘The crew quarters are in the next hut in the line . . .’

  Deirdra, evidently interested, slowed down to look at the ice. Malenfant and Josh slowed with her.

  The others had walked on, leaving the three of them behind. Malenfant didn’t imagine it mattered; there was a sort of informal formality about the whole event that was another characteristic of these British, he was observing.

  He peered up at that rippled roof. ‘That can’t be iron. Some kind of lightweight alloy?’

  ‘Not quite,’ Morris said with a grin. ‘We use water ice. I mean, as a building material. It’s so cold here, it can set as hard as concrete. We use metal cables to enable it to withstand tension – like reinforced concrete, you see. And we are experimenting with doping it with dust to improve its resilience . . . Well, we don’t need to build for structural strength, not here. You might have observed the roofs of all the huts are heaped over with loose ice – Melinoe ice, of course. Masterpiece of field improvisation. We use the big ice-extraction machines designed to fill the electrolysis tanks, and just spray the stuff over the structures.’

  ‘Ice for radiation shielding,’ Malenfant said.

  ‘Indeed. Cosmic rays, a perpetual hazard in locations like this – although Persephone itself has a healthy magnetic field, stronger than Earth’s. Which would shelter life forms on the surface. Here on Melinoe, of course, we have to dig deep into the ice to find the local life.’

  Deirdra and Malenfant shared a startled glance.

  Morris gestured at the floor, the stained ice under the glassy cover. ‘Strange to think of a whole life domain, on a microscopic scale, going on under one’s feet. Of course there are bacterial communities infesting the deep rocks on Earth, but here this is all there is. Very fragile: we inflict an extinction event every time we dig down for samples. Can’t be helped, sadly. And the heat leaking from a human-habitable environment such as this is rather more of a hazard, actually. But the cycles of life here are so slow that the sampled ecology is scarcely inconvenienced.’

  ‘Josh.’ Malenfant held up his hands. ‘Slow down. I think we’re both baffled here. You’re talking about life? Life here on Melinoe, this crummy little ice moon?’

  He seemed surprised to be asked. ‘Well, certainly.’

  ‘It’s not where you found it that surprises me, but that it exists here at all. Native life? I mean, not some kind of leakage from the base, a contamination—’

  ‘Oh, no. The microbiology proves it. A variant on the terrestrial design, actually. The bugs here are based on an identical suite of amino acids, though with genetic data carried through RNA complexes rather than DNA, and I think that may be something to do with the sparseness of the available energy, the deep cold and so forth. Life must live at a slow pace here; perhaps the genetics has adapted as well as the exterior morphology. Still, it’s the same basic machinery of life as on Earth. But it’s not from the Earth.’

  Deirdra looked baffled. ‘And it’s not life from Persephone? Commander Lighthill mentioned that you found traces down there too.’

  He smiled. ‘Again, that’s theoretically possible; one could imagine hardy bugs being blasted even out of that deep gravity well by impacts. But, again, the microbiology doesn’t fit. The life forms down there are different again from those up here – almost as different as we are from either.’

  ‘But,’ Deirdra said, ‘I still don’t see how there can be life here. What does it live on?’ She glanced around vaguely at the roof. ‘The Sun is out there, and it’s brighter than a star but it’s just a pinpoint . . .’

  ‘Good question,’ Josh Morris said. ‘There is energy here. But just a trickle, compared to the flood that Earth gets. Feeding on that, life grows slowly. But it grows . . .’

/>   He spoke of raw materials in this comet-like moon, of water ice laced with nitrogen and carbon and complex carbohydrate molecules, relics of the cloud of gas and dust from which the Sun and its planets had evolved in the first place. And of a slow battering of those compounds by the attenuated sunlight, and by a drizzle of cosmic rays – particles hurled from supernovas and other galactic calamities – and by an equally slow pumping of energy by the ice tides raised in the little moon’s structure as it circled the great mass of Persephone. There was even a gradual leakage of energy from trace radioactive compounds buried deep in the ice itself.

  ‘Doesn’t amount to much. But all these tiny events can create free radicals – that is, molecules that are ionised, trace substances that are highly reactive, chemically. These build up in the ice, slowly, slowly – the low temperature preserves them, you see, so you can get quite a concentration – and that is enough to power simple forms of life, very slow, very small-scale metabolisms.’ He gestured at the brown traces in the surface of the ice. ‘As you see, growing in the upper layers of the ice. That’s the foundation of a food chain, with more complex bacterial types, even colonies, deeper down, feeding on the communities of surface life forms. Here on Melinoe, life grows in towards the centre, where there is more residual warmth and energy, not out towards the Sun, as on Earth. I think it’s possible there are some quite complex life forms buried deep down beneath the surface here, even kilometres down, but we haven’t yet been able to drill down that far. Some day . . .’

  Malenfant and Deirdra shared a glance. Malenfant felt utterly unprepared for this cascade of revelations.

  Josh looked from one blank face to the other. ‘You know nothing of this? You spent years on the Harmonia.’

  ‘To be fair,’ Malenfant said, ‘mostly asleep.’

  ‘Ah, yes. The Wing Commander did say something about that. You must tell me all about that technology . . . But as to Melinoe life, I think I am shocked that the crew didn’t mention that at all. I mean, look at it! Isn’t it spectacular?’

  He waved a hand at pale brown smears, barely visible in the glassed-over ice.

  Malenfant clapped him on the shoulder. ‘In another life I’d have ribbed you for that remark, kid. But not here. Not now. This is a wonderful discovery. And if those assholes with their tobacco and brandy and old-school talk don’t appreciate it – you’re right, they didn’t even bother to mention the discovery of life, here in this place – that doesn’t make it any the less remarkable.’

  Morris seemed unreasonably pleased. ‘Thank you, Colonel.’

  ‘Call me Malenfant.’

  ‘But,’ said Deirdra, ‘if there’s so little energy how could life have evolved here in the first place?’

  ‘Oh, it probably didn’t,’ Morris said casually. ‘It was obviously seeded.’

  Malenfant frowned. ‘By what? A comet impact or such?’

  ‘Oh, no. By whoever seeded Persephone also. The amino acid suites are identical – that alone is enough to rule out chance parallel evolutions.’

  ‘You said – whoever?’

  ‘And whoever seeded Earth too.’ Morris glanced around. ‘Come on! I think we’re being left behind.’

  He hurried off along the track, over the glistening, bug-ridden ice.

  Deirdra stared at Malenfant. ‘Did he really say that? That somebody, or something, seeded life across the Solar System?’

  ‘Sounded like it to me.’ He had never told her of his discussion with Karla, the Planetary AI who had similarly speculated that some agent had ‘seeded’ the inner planets with a common life stock. And now, this fussy kid from another reality with precisely the same suggestion. Soon might be the time for more openness about it all, to share what they all knew . . . He forced a smile. ‘Totally unexpected news, right? Now you know what it’s like getting woken up in an ice box after centuries asleep.’

  ‘Maybe. And you know what it’s like being young. Come on, Malenfant.’

  And they followed Morris, hurrying as best they could in the ice moon’s feeble gravity.

  62

  A week after the arrival of the Harmonia at the Melinoe base, preparations were made for a journey down to the surface of Persephone.

  Once he had learned that such expeditions were made, Malenfant began a subtle campaign to be given a place in a landing party. Aside from what he might find down there, he was curious to learn how exactly you managed a descent into the deep gravity well of what the planetary astronomers in his timeline had called a ‘super Earth’, an Earthlike world but bigger.

  To questions about which, base engineer Guy Briggs would only reply, languidly, ‘Very carefully. I like the term, though. Super Earth.’

  At last Nicola Mott took pity on Malenfant.

  ‘You may not have worked out the dynamics of the crew rotation here, Malenfant,’ she said. ‘Look, the RASF is a pretty ambitious organisation – and so are the people who work for it. And here at Persephone-Melinoe we are right at the limit of what is achievable technically, and affordable financially and politically.’

  ‘You’re telling me there is competition to be here.’

  ‘And once you are here, competition for the glamorous stuff, like a descent to Persephone. We don’t do it that often.’ She smiled. ‘I imagine space travellers across the manifold have similar pressures, and ambitions. Too many super-capable crew chasing too few opportunities. Well, here the permanent staff at any time is only three. The Harmonia shuttle brings replacements, but the philosophy is that at least one of the previous rotation stays aboard the station, for continuity. In this case that’s to be Bill McLaurin, the commander. So Geoff Lighthill will fly onwards to Shiva, with Morris and Briggs. I will be replacing Josh as science specialist, and Bob Nash will take over from Guy Briggs as engineer. A three-year tour, for us, until Harmonia’s sister ship comes to take us off. And three years after that, Harmonia herself will return from Shiva. And so on.’

  Malenfant thought that over. ‘But even so, given the journey, a tour away from Earth is, what, at least nine years? Even if you go no further than Persephone. Three years each way there and back, a minimum of three years on the station.’

  She shrugged. ‘Colonial postings around the Empire – I mean on Earth – can be much longer. And such tours are generally regarded as the peak of one’s career, Malenfant. Once in a lifetime. Wish I could say the pay was good. But one can expect a promotion afterwards, and a bit of tin or two.’

  ‘Bits of tin? Oh. Medals.’ He hesitated. ‘When I woke up in this century, I found out you and I gathered a few of those posthumously, after the Constitution crash.’

  ‘She wasn’t me, Malenfant,’ Mott said gently.

  ‘I know. But . . .’ But I can’t help seeing her in you. Like I see Emma in Emma II. And it hurts, all the time.

  ‘Let’s stick to Persephone,’ she said.

  ‘Persephone, yeah. So why are you telling me about crew rotations?’

  ‘Because I’ve just heard about the crewing of Charon for its next descent.’

  ‘You mean the planetary lander? Why Charon?’

  She grinned. ‘I think he was the chap who piloted the boat across the river Styx, which divides the worlds of the living and the dead.’

  ‘More classical bullshit. But appropriate enough for Persephone, I guess. OK. And the crew is going to be?’

  ‘Well, Charon is a four-seater – actually it can take more at a pinch. I’m going. Geoff Lighthill is going to pilot – gives him one chance to see the planet before Harmonia whisks him onwards. Guy Briggs, the engineer, will represent the outgoing crew. But that’s appropriate in this case, because we are planning to visit one of the Towers, which has been his pet study.’

  Malenfant felt a surge of excitement. He tried not to show it. ‘The Towers. Those structures along the equator.’ He knew the Brits capitalised the word in their reports.

  ‘I think there is a feeling back home that we haven’t done enough to explore those beasts – what they
are, how they work, what they are for. And, bluntly, what we can learn from them. Guy does say he has got a lot further in his investigation than he has been able to report so far. Secrecy is a habit, and important results aren’t sent back by radio but couriered home aboard the Harmonia and its sister ship. Don’t want them falling into the hands of our rival powers, you see. So this is a conversation that spans years. But even so the brass are impatient.’

  He nodded. ‘Just as with Phobos. You imperial types are out here to grab any alien-tech secrets you can get your hands on, ahead of your global competitors.’

  She frowned. ‘It’s not our strategic goal to come second, Malenfant.’

  ‘OK. And the fourth crew member?’

  Now she grinned. ‘You have me to thank. Look, you aren’t one of the trained crew. You’re a mere passenger. But as a representative of an entirely different cultural tradition, you may just come up with fresh insights. You never know, it’s worth a shot – that was the argument I made, anyhow. Pack your toothbrush, Malenfant.’

  Malenfant whooped, and offered her a high-five palm. Embarrassingly, she had no idea what he was doing.

  And so, the next day, Malenfant found out how you landed on a super Earth.

  63

  The Charon looked to him, at first glance, like another variant of the Apollo Lunar Module – an obvious design, like Viktorenko’s ship at Phobos, for landing on an airless world – but this one was bulked up, reinforced. Muscular. He guessed that this beefy lander was going to use a variant of the Brits’ fusion drive to land on Persephone, and, defying the giant world’s gravity, haul ass out of there again.

  He walked around the craft. There were wide downward-looking windows, like blisters, that would give a great view during the descent. And big rocket bells, obscured by those landing legs, and fat, lumpy propellant tanks. Also he saw mounting brackets where, he found out, heat shield panels and aerosurfaces could be mounted, if an entry into a thick atmosphere was mandated.