Authors: Stephen Baxter
Trant grunted. ‘We had to custom-design the system. We’re going too deep for conventional cables, even under the low gravity. We fitted the car with crawler attachments; we’re
clambering down the walls of the shaft.’
‘
Too deep
,’ Stef repeated. ‘How deep?’
‘Over four hundred kilometres,’ Trant said, with a touch of pride – justifiable, Stef thought. ‘We’re going all the way to the base of the planet’s crust. To
the fringe of the mantle, in fact, which is where the kernels are found.’
‘It’s quite a trip,’ King said. ‘All this is hush-hush at present, you understand, but I have got a couple of tame journalists documenting all this for the history books.
I’m given to understand that a crewed trip to the edge of a planetary mantle has never been achieved elsewhere, not even on Earth.’
Stef thought over what she knew about Mercury. ‘I thought the prevailing theory is that Mercury suffered a tremendous impact, back in the age of planet formation. The whack shattered and
stripped away the planet’s upper rocky layers. Right?’
‘That’s one theory,’ Trant said. ‘There’s another that’s doing the rounds here. Informally, I mean. That whatever incredible event created or implanted the
kernels on Mercury might have caused a huge convulsion of energy, a convulsion that nearly blew the planet apart.’
‘Wow,’ Stef said, impressed, but she reached for her native scientific caution. ‘Quite a hypothesis. Have you got any way of proving it?’
King said, ‘I rather think that’s why you’re here, Major Kalinski.’
The elevator car slid to a smooth halt, and the shaft walls seemed to lift like a curtain. Stef found herself looking out into a cavern, flat-roofed, cut into the deep rock. This cave, hundreds
of kilometres under Mercury’s surface, was brightly lit, and there were more small domes, pressurised facilities, marked with UN and UEI sigils.
The purpose of the cavern was obvious too. Armed troopers in military-specification pressure suits stood in a loose circle around what looked like an unprepossessing patch of floor. Stef saw
that scientific equipment of all kinds had been assembled around this bit of floor; lenses and other sensors peered down, and there was an industrial-strength laser mount. Something about the whole
set-up, the sheer bizarreness of finding a science base and security cordon hundreds of kilometres deep under Mercury, made Stef’s heart hammer even harder.
‘Time to close up your suits,’ Trant said. ‘We’ll run through another full integrity check before stepping out of the car.’
Stef was glad of the long minutes of routine that followed. Since arriving in Mercury orbit she felt as if she had fallen too quickly into this place, this pit bored into the deepest rocky heart
of the solar system; she needed time for her soul to catch up with her body.
At last the car door opened, the air sighed out, and Stef walked out, heading towards the circle of troopers, the enigmatic patch of floor they protected. She was locked inside her suit,
listening to the air-circulation fans and her own noisy breathing. The troopers let them pass. And as they neared the very centre, King and Trant too stepped back, allowing Stef to walk forward
alone, staring at the floor.
And there, set in the rock of Mercury, buried under hundreds of kilometres of crustal layers for billions of years until dug out by questing human hands and tools, was –
A hatch.
S
tef walked around the emplacement, trying to absorb the physical reality of it. Trying to observe rather than analyse, for now, the best strategy
when faced with the utterly unexpected.
What did she
see
?
She saw a panel, a rough square of some seamless, pale grey material – metal, perhaps, or ceramic, or some unknown material altogether. It was maybe ten metres across. And at the centre of
the panel was a circle, a fine seam engraved into the plain material, perhaps three metres in diameter. That was all, there was no further marking or indentation.
She turned to face King and Trant, who looked at her expectantly.
‘Well?’ King snapped. ‘You see why we didn’t tell you? You see why you had to look for yourself? And you see why we told Earthshine? It’s hard to think of a more
significant development for the future of the human race.’
‘It’s obviously artificial,’ she said. She turned back. ‘Obviously – a hatch.’
Trant grinned. ‘That’s what everybody calls it. A common first reaction. In the internal reports we capitalise it.
The Hatch
,’ she said heavily. She turned, gesturing
at the walls. ‘There are kernels all through this layer. You could pick them out by hand. And in the middle of this rich lode, we found – this.’
‘How did you detect it?’
‘Initially by traces in deep radar pulses, seismic traces. Some very strange echoes.’
Stef knelt now, beside the emplacement. The panel looked about a couple of centimetres thick. ‘Is it safe to touch?’
‘Be my guest,’ Trant said.
Stef set her right hand on the material. She felt nothing. ‘I wish I didn’t have to wear this damn glove.’
‘The material is actually a good deal cooler than the ambient temperature.’
Stef drew her hand back over the edge of the panel, and felt an odd pulling sensation. She tried again, passing her hand back and forth over the edge; it was a kind of tide, a sideways push,
like passing a charged iron rod through a magnetic field.
‘We don’t know what it’s made of,’ Trant said. ‘Needless to say. We’ve tried cutting it, with low-level lasers; it just soaks up the heat. There are more
destructive tests we could try, but we’ve been reluctant to go that far.’
Stef knew there had always been loose talk about the kernels possibly being artefacts of intelligence. They might or might not be. It was hard to dismiss the Hatch as anything
other
than an artefact – what natural process could produce an object with this regularity? ‘Do you think it’s in any way associated with the kernels?’
‘Well,’ King said, ‘we found it in the same layer as a rich kernel lode—’
Trant said, ‘It seems coincidental if they aren’t associated. To find two extraordinary things in one location – assuming a link exists is the simplest hypothesis.
Occam’s razor, Major Kalinski?’
She ignored the gentle goad. ‘I don’t suppose you’ve tried opening the Hatch.’
Trant said, ‘That seam, whatever it is, is too fine for most of our tools. We could try harder . . . Anyhow, it would be futile.’
‘How so?’
‘Because the Hatch is just a mask. A plate sitting there on levelled-off rock. There’s nothing underneath it. We’ve proved that with sonic and radar probes, and by drilling
into the rock under the Hatch.’ She pointed to a couple of small pits.
Stef got to her knees again and examined the Hatch, running her fingers along its thickness. Again she felt that odd sideways push. ‘Have you measured its volume?’
‘I can tell you the calculation.’ Trant pulled a slate from a pouch in her suit leg, and fiddled with it. ‘We’ve got precise measurements of every
dimension—’
‘No. That’s a calculation. Length by breadth by height. Have you
measured
the volume?’
Trant seemed baffled. ‘No. I mean – how?’
Stef stood up. ‘What have you got in the nature of fluids down here? Water, lubricants . . .’
It took a couple of hours to set up the experiment. They rigged up a dome over the Hatch that would hold pressure, and pumped it full of non-reactive nitrogen. Then they poured in lubricant, an
inert hydrocarbon borrowed from the elevator assembly, that flooded the emplacement.
It was fiddly work in pressure suits and with improvised equipment, but once Stef had communicated what she wanted the engineers worked quickly and effectively, even though some of them grumbled
about the risk of wasting the lubricant, a precious resource here on Mercury. It was always the same with engineers, Stef had observed; nothing made them happier than to be given a well-defined and
achievable task, and to be left alone to get on with it.
So they measured the volume of the Hatch and its emplacement directly, from the displacement of the lubricant fluid. She had them repeat the measurement a few times for accuracy.
The direct measurement differed from the result obtained by multiplying together length, breadth and height.
‘It’s too big,’ Trant said, wondering. ‘Ten per cent or more . . . Too big for any errors.’
‘I don’t understand,’ King said, grumbling. ‘I can’t get my head around this. All this mucking about with engine oil!’
Stef grinned. He seemed disappointed she hadn’t ordered some vast super-physics experiment to be run. ‘Sir Michael, it’s as if you have a one-litre jug, only it holds two
litres.’
‘It’s bigger on the inside than the outside?’
‘Something like that. There’s some kind of distortion of space-time going on here.’ The dome had been cleared away now, the Hatch revealed again, the last of the lubricant
fluid removed. Stef knelt and touched the panel surface once more.
Trant was staring past her. ‘Major—’
Stef passed her hand over the edge. ‘Just like before, I feel something, like a tidal effect.’
‘Major Kalinski, I think—’
‘And just as the kernels are evidently some kind of space-time phenomenon, so is the Hatch—’
‘Stephanie!’
King snapped.
Stef was startled into silence, and turned. Just for a moment King had sounded like Stef’s father, as King had surely intended.
Trant, glaring, was pointing at the Hatch. ‘Shut up,’ she said evenly. ‘Turn around. And look.’
Stef turned, needles of icy anticipation prickling along her spine.
The Hatch had changed.
That smooth surface, within the circular seam, was smooth no more. A series of indentations had appeared, set evenly around the edge – they came in pairs, twelve pairs,
she counted quickly, like the numbers on an antique clock dial. The indentations themselves were complex in shape, with a textured central crater, and five channels running off in a lopsided star
shape.
‘Hands,’ King said. ‘They’re meant for human hands.’
Stef saw it as soon as he said it. Somehow she’d been blinded by the obvious, by the incongruity of the setting.
‘The imprints of human hands,’ Trant said slowly. ‘On an artefact that’s nearly as old as Mercury itself. That’s been here forty thousand times as long as humanity
has even existed.’
‘More to the point,’ King said, ‘imprints that weren’t there a minute ago. Not before Major Kalinski ran her experiment with the lubricant.’
‘And,’ Stef said carefully, ‘before we made our very first deduction about it. Suddenly it knows we are here.’
Trant guffawed. ‘It
knows
? Now who’s hypothesising about agencies?’
Stef ignored her. ‘The purpose seems obvious.’ She stepped up to the Hatch, and knelt beside it once more. She held out her hands, and again felt that odd tidal ripple. Had the
quality of that sensation changed at all? Her senses didn’t seem subtle enough to be able to tell. She looked back at King and Trant, at the technicians and guards behind them, all in their
ISF pressure suits, like so many robots. All of them staring straight back at her. As if daring her.
She turned, spread her gloved fingers, and extended her hands so they were over one of the indentation sets. But she held back from touching the surface. Should she do this? The Hatch had
changed, it seemed, the minute she had figured out something about its true nature.
It had responded
. How would it respond, what would change, if she went one step further now?
Only one way to find out. Oddly she wasn’t afraid any more.
She settled her hands into the indentations. Gloved, they seemed to fit perfectly.
And the Hatch immediately began to open.
Trant grabbed her shoulders and pulled her back, bodily lifting her in the low gravity.
They stood and watched as the huge circular plate lifted out of its seam, attached to the emplacement by some invisible hinge – how
was
it being held? Stef bent to see. The rising
lid just touched the wider emplacement at its rim. There seemed no material attachment.
And again she’d had her eye off the ball; she wasn’t observing the most striking phenomenon. Under the rising Hatch was revealed a chamber, cylindrical, maybe four metres deep, set
in the Mercury rock. It seemed to be made of the same greyish substance as the rest of the installation, and it was lit by a sourceless glow.
‘That’s impossible,’ King said.
‘You are right,’ said Monica Trant. ‘There’s nothing but rock under that plate. We
measured
it.’
But Stef could see the glow coming from the impossible pit reflected in their visors, their staring faces, baffled. She felt a peculiar exhilaration. This wasn’t like her at all. Most of
her life, her science, had proceeded in cautious, methodical steps, with each new extension of her knowledge building incrementally on what had gone before. Now all that was thrown out; now she was
rushing headlong into the unknown, the non-categorisable, the unidentifiable, in a way she’d never imagined.
This wasn’t Stef Kalinski’s way. She was thrilled. She could barely wait for the next step.
As soon as the Hatch lid had come to a halt, standing vertically from its invisible hinge, Stef walked forward to the edge. ‘Monica. Give me a hand.’
‘You’re going in there?’ Trant glanced at King, who shrugged. Trant said, ‘I don’t know how wise this is.’
‘We’ve come this far. It’s obvious what we’re meant to do next. We can’t stop now.’ Stef glanced up at the rig of cameras and sensors all around the
emplacement. ‘We’re being recorded, right? Whatever happens, those who follow us will know what became of us.’
‘Yes. But this doesn’t seem too scientific, Stef. Just to plunge in.’
‘This isn’t science. This is exploration.’
‘No,’ King gloated. ‘Let’s be honest. It’s appropriation. It’s conquest. It’s going to kill those gerontocrats in New Beijing, when they read about this
day, when the security blankets are lifted in fifty or a hundred years’ time, that we haven’t just got the kernels – now we have
this
.’