Proxima

by Stephen Baxter

  ‘Like the ones our engineers run down in the engine rooms of hulks like the Shrapnel every day,’ Trant said drily. ‘I know. Well, given the strangeness of what they seem to have found on Mercury, they’ve decided they need theoreticians after all. So fill your boots.’

  They reached a security gate set in the base of the hulk, where a crewman held them up to verify their security-scan access to the engine room. Stef, weightless, clung to her pole and peered up into the great tank of the ship’s hull, brightly lit by fluorescent strips. On this trip the hull was more or less empty – incredibly, the main purpose of this high-velocity interplanetary flight seemed to be to bring her to Mercury – but she could see brackets and shadows in the paintwork where partition floors, loading cranes and other fixtures could be fitted. Right now ISF crew swarmed in the air, taking the chance to clean out clogged air filters and perform other chores in corners hard to access under gravity.

  A hulk like this was regularly used to transport massive cargoes between the planets. Science samples, for instance. A century back, planetologists had crowed about samples returned to Earth from Mars by robot craft, samples which had been measured in grams. Now they brought back rocks that weighed tonnes, and kilometre-long cores of Martian polar ice. They had even run an experimental ship across interstellar space, to the habitable world that had been detected orbiting Proxima Centauri. And, routinely nowadays, hulks like this were used to transport hundreds of colonists to the UN bases on the moon and Mars. Stef thought she could smell the stink of all the people who had travelled in this ship, sweat and urine and baby milk, suffused into the very fabric of the ship.

  Monica Trant saw her looking. ‘Not pretty, is it? But very effective. The Shrapnel is one of the more reliable members of UEI’s little interplanetary fleet.’

  ‘Why Shrapnel? I thought the ship’s name was Princess Aebbe.’ In the passenger lounges there were little animations of the launch of the ship from its dry dock at an Earth-moon Lagrange point by the youngest daughter of the North British King, and the royal family’s ‘Fighting Man’ standard was splashed in lurid red and gold all over the hull, amid UN roundels and UEI logos.

  ‘So it is. But all these hulks have more familiar names given them by their engineers. We don’t trust the kernels because we don’t understand them. So – the Mushroom Cloud, the Shrapnel, the Pancake.’

  ‘Black humour.’

  Trant looked at her quizzically. She was in her late thirties now, her hair greying and pulled back, but she looked fit, lean, clearly competent in her world. ‘Black humour, yes. You don’t spend much time around people, do you? I always remembered that about you, even when we were running Angelia from Yeats with your father. You were a withdrawn little kid, always had your nose pressed up to some screen or other.’

  ‘You know kids, do you?’

  ‘I’ve one of my own. Little Rob. Two years old now. Back home with his father . . .’

  ‘You didn’t stick around long on the Angelia project.’

  Trant seemed cautious. ‘I lasted a few years. Since Angelia went quiet there’s been nothing to do but archiving and recontact attempts. Look, Major—’

  ‘Call me Stef.’

  ‘Sure. No offence, I know Angelia was your late father’s pet project, but it was obsolete before it was launched. So I moved to where the action was, the new field of kernel engineering. As did you, in a way, right? I used contacts I made at the launch of the I-One. And now I’m one of UEI’s top internal consultants on kernel engineering. That’s how life is.’

  Stef shrugged. Personal conversations like this, about people’s excuses for their life choices, didn’t interest her much.

  ‘And you ought to feel honoured,’ Trant said now. ‘These craft hardly ever fly empty, not since their proving flights. They must really want to get you to Mercury, huh?’ She sounded faintly envious.

  ‘I hope I can make a contribution,’ Stef said neutrally.

  At last the crewman got their access approved. He opened the hatch, and they passed out of the hulk’s big internal space, down through a thick bulkhead. They had to cycle through a kind of airlock, and Stef was aware of various kinds of security scans being run; shimmering lines, laser guides, swept over her.

  ‘Just routine,’ Trant said.

  ‘Why’s it necessary? If any sabotage was attempted to the drive, probably the whole ship would be destroyed, saboteur and all. The energies are such that—’

  ‘I do know,’ Trant said, a little testily. ‘But we carry hundreds of colonists across the solar system, and some of them figure out on the way that they’re not too happy about becoming colonists after all, whether or not they were given a choice about it. They can get kind of desperate. People don’t always act rationally, Major Kalinski. And then there’s the Chinese factor.’

  ‘You can’t be serious.’

  ‘Well, there you have a major power who’s still excluded from any share of this advanced, and very powerful, technology. If the UEI and ISF aren’t riddled with Chinese spies, if not saboteurs, I’d be surprised. So we take security seriously.’

  They were passed through, and dropped down into a rest area, with a lavatory, a couple of bunk beds, a small galley.

  And here Sir Michael King was waiting for them, loosely strapped to a couch, sipping coffee through a plastic cup with a nozzle. He was wearing a kind of coverall, deep royal blue, cut to fit his squat, heavy frame, that simultaneously looked practical and expensive. When Trant and Stef entered, swimming down from the ceiling, he pushed himself out of his chair. ‘Glad to see you made it down here, Major Kalinski.’

  ‘Why wouldn’t I, sir?’

  ‘Most passengers, especially those from Earth, spend most of their time during the accel-decel handover locked in their cabins chucking up.’

  ‘I’m a veteran of the Earth-moon run. My body’s used to microgravity.’

  ‘Well, mine isn’t,’ King said. ‘I had to swallow a whole pharmacopeia.’ He grinned, his face pale, sweating. ‘But I wouldn’t miss it for the world.’

  Trant nodded at the ISF crewman who, discreet and unspeaking, had followed them in here. ‘Let’s get on with it.’

  The crewman opened another hatch, in the floor. Below, Stef saw, was a kind of carpet, speckled with lights that shone bright in a relative gloom. They followed the crewman down through the hatch, and spread out.

  There were three, four crew already in this wide chamber, in their jet-black ISF uniforms, swimming over the illuminated carpet, carrying slates, making notes and murmuring to each other. The ‘carpet’ was actually another bulkhead that spanned the width of the hulk, Stef saw now, and the lights that sparkled in the floor, more or less uniformly distributed, were a display. Flux lines swept between the lights, uniting them in a pleasing, swirling geometry – a three-dimensional geometry, Stef saw, as she shifted her head from side to side. The whole was littered with tiny labels, numbers and English letters; the systems sensed whatever she was looking at, and the labels magnified in her vision.

  Trant said, ‘This is our engine room. We run everything through this one display. Under acceleration, this is a floor under our feet, but in microgravity it makes more sense to treat it as a vertical wall – you can see there are hand- and footholds . . .’

  Sir Michael King was watching Stef intently. ‘This is as close as we can get to the real action. I mean, I understand the display we see here is just a representation of the reality, but . . . Can you feel them, Major? I know you’ve been around kernels for years, but not an array like this. Can you sense them? Can you feel their energies?’

  And Stef thought she could, yes, a kind of tide that pulled at her body as she hung there in the air – a tide from the space-time knots of the kernels themselves, perhaps, or maybe a force exerted by the powerful magnetic fields that held them in place, a great wall of them contained not metres from her position. She felt thrilled, viscerally, physically; the pathetic handful of kernels in the lunar labs would have been lo
st in this huge assembly.

  King said, ‘Here you are, confronted by the mystery. Tell me about kernels, Major Kalinski.’

  ‘I can tell you what we think we know. Which is precious little.’

  He pulled a face. ‘And I could tell you how much that inadequate reply has cost me so far.’

  ‘Sorry.’

  He said, ‘I know a kernel is a twisted bit of reality. Like a black hole, right?’

  ‘That was our first guess. Black holes are similarly twisted bits of space-time, yes, the remnants of imploded giant stars, or maybe relics of the Big Bang. And all black holes radiate; they leak energy from their event horizons, and the smaller they get the hotter they are. But nothing fit. A kernel masses only kilograms, a lot less than any but the most evanescent black hole. And the energy it emits isn’t black-hole Hawking radiation but something much more exotic, a flood of high-energy photons and very high-speed particles, like cosmic rays. Also, the way the energy leaks from a kernel depends on the way you prod it.’

  ‘You mean with laser beams,’ King said. ‘Well, I know about that. A lot of lives were lost to establish that simple fact. And Mercury gained itself a new crater.’

  ‘By manipulating it with laser beams you can shape the way a kernel releases its energy store. Get it right and it can even be unidirectional.’

  ‘Like a little rocket.’

  ‘A microscopic photon rocket, yes. And that’s what makes them so useful. The kernels carry an electric charge, and are so light that a powerful enough magnetic field can hold a whole bank of them in place, just as in this ship, behind this bulkhead. Fire the control lasers just right and they all open up, and you get a kind of photon rocket.’

  ‘Driven by a light as bright as the sun,’ King said. ‘Visible across interplanetary distances. Hell of a thing. After all these years, you know, I still can’t get used to the sight. But what I want to know from you, Major, is how the damn things work. Where does all that lovely energy come from?’

  ‘Well, not from the structure of the kernel itself – it’s not massive enough for that. Our best guess is that a kernel is less like a black hole than a wormhole—’

  ‘A tunnel in space.’

  ‘Yes.’

  ‘I thought wormholes were impossible,’ Trant said. ‘You need some strange kind of matter to keep them open.’

  Stef always got irritated when some lay person asked her a question and then started lecturing her about the answer, rather than just listening. She snapped, ‘It may have looked that way according to the kiddie Einstein-relativity stuff you learned at high school, Monica, before you gave up science for engineering. Have you ever heard of a dilaton field? No?’

  Monica Trant looked irritated.

  King raised luxuriant eyebrows, amused. ‘Well, that’s put you in your place. Let’s get to the basics. A wormhole is a tunnel, right? From here to . . . someplace else.’

  ‘That’s right.’

  ‘So the energy that flows out of a kernel, the energy we harness to drive our hulks, doesn’t come from the kernel itself. It comes from someplace else, and is just transmitted through the kernel.’

  ‘That seems to be true. The ultimate power source must be some very energetic event, somewhere else. A gamma-ray burster, maybe. Could be from the future or the past.’

  Trant frowned. ‘What do you mean by that?’

  ‘The wormhole could connect you to any other point in space and time, sir. Or—’

  King waved a hand. ‘Enough, enough. You know, Major, some people are suspicious of the kernels. I mean, their very existence. Your own father was, right? There we were struggling to come up with ways to reach the stars. And now we’ve been handed this magic power source, on a plate, and we’re off to Proxima Centauri. We needed a miracle, and suddenly we had one. The problem is, you see, Major, in business or in politics, hell, in most marriages, if I give you something, it’s generally because I want something of you in return. So what’s the catch?’

  ‘You’re assuming agency,’ Stef protested. ‘Intervention by some kind of consciousness. It’s better to rule that out until there’s overwhelming evidence. Occam’s razor: you should default to the simplest explanation, and natural causes are the simplest explanation we have for most phenomena. Including the presence of kernels on Mercury.’

  Trant said, ‘Wait until we get you to Mercury, Kalinski.’ She shook her head. ‘Occam’s razor. Jesus.’

  A gong sounded, echoing around the ship.

  King turned to the ladder up to the main hull. ‘They’re about to fire up again. You’ll find me in my couch, until my old bones get used to gravity again . . .’

  Stef was allowed to stay down on the control deck, with Trant, the two of them strapped into acceleration harnesses, watching as the highly trained crew went through the process of firing up their laser banks, opening up their tame space-time knots, and allowing their unknown-source energy to stream out.

  And the tremendous mass of the hulk was once more hurled forward into the heart of the solar system.

  CHAPTER 37

  At Mercury the Shrapnel entered a low equatorial orbit, and a small, low-powered shuttle flew up to bring Stef, King, Trant and a couple of ISF guards down to the surface. The little ship was piloted by ISF officers, who saluted Stef when she boarded while simultaneously security-scanning her. The shuttle had only one cabin, fronted by the pilot with the passengers in the back, and while the passengers strapped in Stef heard the crew talk through more complicated security protocols. Evidently this wasn’t a place where casual landings were welcome.

  They came down in a sweeping powered descent across a shattered landscape. The shadows of crater-rim mountains, wave after frozen rocky wave of them, stretched across broken lava plains.

  Trant turned to Stef. ‘Do you know where you are? On Mercury, I mean.’

  Stef shrugged. ‘I only came back once to Mercury since the Angelia launch. It was a memorial service for my father after he died, given by the staff he worked with here.’

  ‘I know. I was there, though we didn’t speak.’

  ‘I think this must be the Caloris basin.’ A tremendous impact crater that dominated one face of the planet. ‘Given the scale of the cratering features.’

  ‘Correct. The result of an impact that couldn’t have been much bigger, to have left any planet behind at all. I suppose you don’t need to know much about Mercury to guess that much.’

  ‘I’ve had no briefing,’ Stef reminded her testily. ‘So it’s to be guessing games, is it, all the way down?’

  ‘We want you here to take a fresh look at what we found. I suggested it was best not to prejudice you in any way. Blame me, if you like.’

  Stef felt a shiver of awe, flying over this tremendous ruined landscape, which itself concealed a much more exotic mystery. What the hell were they being so secretive about?

  On the ground, in the chaotic shadows of Caloris, they were bundled into a rover. There was a driver and a couple of crew, all in ISF uniforms. The two security goons who had come down from orbit with them followed too. Making her way to a seat in the rover, Stef experienced a gravity that was twice the moon’s, a third of Earth’s, a gravity that felt oddly familiar, a body memory from her childhood.

  The rover rolled off, and through the small windows Stef glimpsed the landscape of Mercury, for her a peculiar mix of alien and familiar. The sun was just below the horizon here, though a smear of coronal light spread up into the sky. The shuttle landing site behind her was lit by brilliant floods.

  ‘Here.’ Trant opened a hatch and pulled out pressure suits. ‘One each. We’ll suit up en route in the rover.’

  King awkwardly hauled his own suit over his bulk. ‘We’re making straight for the site.’

  Stef asked, ‘What site?’

  Trant said, ‘This is, or was, just another exploratory drilling site.’

  ‘You were looking for kernels.’

  ‘Essentially, though Mercury is also still exporting
metals to the rest of the inner system. Stef, you’ll find dormitories in the well-head domes, showers, galleys. If you need a break before we descend . . .’

  Descend into what? Every bit of information they gave her seemed to lead only to more questions. Let them play their games. ‘Let’s just get on with it.’ Trying not to let their evident urgency transmit itself to her, she pulled on her suit, ISF standard issue, a piece of kit she was used to. The smart fabric slid into form-fitting shape around her; as the suit recognised her a panel on the chest lit up with her mugshot, rank, commission number, name: KALINKSI, STEPHANIE P.

  King smiled. ‘That’s correct, isn’t it? P for Penelope.’

  Stef pulled a face. ‘A name I always hated even more than “Stephanie”. So you found kernels in Caloris, right?’

  Trant looked out at the smashed landscape. ‘We’ve developed pretty efficient ways to prospect for kernels, even from orbit. We look for concentrations of the kernels’ distinctive energy signature, at sites easy to mine. The heart of Caloris has given us some rich pickings, actually. The kernel lodes here aren’t always quite as deep as elsewhere on the planet, and the ancient impact shattered the bedrock, making it relatively easy to get through. “Relatively” being the word.’

  Stef thought that over. ‘Which implies that the Caloris impact came later than whatever event laid down the kernels.’

  King nodded approvingly. ‘That’s what my tame geologists deduce. Even though the Caloris event itself was very old, a relic of the planet-formation days. The kernels have been down there a long time; whatever created them, or implanted them, was a very early event in terms of the history of Mercury – hell, of the solar system itself. So we drilled down into the floor of the crater, and that itself was a challenge, I can tell you. But what we found – well, you’ll see for yourself.’

  The rover had to pass through a couple more security cordons before pulling up at what was evidently a drilling site, dominated by a single massive rig standing on an area of relative flatness. Stef saw hab domes covered in regolith for solar-radiation screening, a few more rigs much smaller in scale, and massive specialised vehicles.