The ColU looked pained. ‘I have created whole fields of terrestrial topsoil at this site.’

‘So we move the soil as best we can, as much as we can. It’s no use here without water. We’ll have to shift our other stuff too. The house, the buildings – maybe we’ll rebuild in some modular form, for when we have to break it all down again.’

‘You mean,’ Mardina said slowly, ‘when the builders shift the lake again, some time in the future.’

‘Right.’

‘Why should they do that?’

‘If they’ve done it once, why shouldn’t they do it again?’

‘The ISF imagined we’d be stuck here, in this place, for life,’ Mardina said. ‘Tied to the lake for its water. Instead, the lake’s migrating, and so are we.’

‘That’s right.’ He grinned. ‘Everything’s changed.’

‘And a door’s opened for you, ice boy. Just as you said it would.’

‘Damn right. Now all we have to do is to step through. And who knows what we’ll find?’

‘ColU,’ Mardina said, ‘what did you say the builder phrase for the lake is?’

‘ “The interface between mother and father which brings life”.’

‘Hmm. And wherever it travels, yes, it will bring life. It is like the Dreamtime spirit that created the rivers and the waterholes. It is a jilla.’

Yuri nodded. ‘OK. Better name than Puddle anyhow.’

The baby started to cry, cold, tired, hungry. The ColU, moving with an oddly balletic grace despite its bulk, turned carefully, disturbing its fragile cargo as little as possible, and headed back to the camp.

CHAPTER 36

The flight by UEI hulk ship from Earth to Mercury was a high-energy straight-line blast across the solar system, at a constant one-gravity acceleration. Constant, save for one six–hour interval of microgravity, when the kernel drive was briefly shut down, the systems checked out, and the ship flipped over to begin its deceleration to the destination.

In this interval, while the drive was inert, Monica Trant invited Stef Kalinski to visit the hulk’s engine room. Led by an ISF crewman, they pulled themselves down a fireman’s pole that ran the length of the axis of the big, spacious tank that comprised the greater part of the hulk, down towards the engines.

‘Thanks for this,’ Stef said to Trant. ‘You know how it is. Since I graduated I’ve devoted practically my entire life to a study of the kernels. But I’ve only ever had access to the handful of specimens donated by UEI to the UN moon labs, and even there we’ve never been allowed to run the kind of high-energy experiments—’

‘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.’