He was still on his hands and knees when the little builders came swarming out after him and scattered.

He got to his feet and followed the smallest, the one he had handled. It made straight for the dense bed of stems where the adult had headed. When he caught up, the adult was standing stock-still, the little one at its side, in the middle of the stem bed. The adult seemed to be facing Yuri, who slowed to a halt.

The ground was slick underfoot, he saw, the mud here thick with lichen, from which the stems were growing. The stems themselves came up to his waist. They were an unusual kind, darker, flatter, more like blades than the usual tube-like structures, yet still substantial, still no doubt filled with marrow. The adult had been collecting them, he saw; it had specimens at its feet, carefully detached from the lichen bed and lain down.

And on every stem, facing him, growing from the muddy ground, a single eye opened.

That was too much for Yuri. He turned and ran, and didn’t stop for breath until he was halfway back to the camp.

CHAPTER 25

When he got back, Yuri found the ColU and Mardina in the middle of an argument.

He blurted out his news. ‘They’re intelligent! They use tools! They have eyes! This is first contact, isn’t it?’ To his dismay nobody was interested in his discoveries.

Before the half-built house the ColU rolled backwards and forwards in the dirt, an odd little habit it had developed, especially when it faced a stressful decision. Mardina sat on a fold-out stool hacking at scrawny potatoes with a knife, slicing them up and then dropping them skin and all into a pot. She had bare legs and feet; she wore cut-down jeans that had once belonged to Martha Pearson, and her curly black hair was pulled back from her forehead. She looked wiry, tough, resilient, practical. She also looked angry.

The ColU at least tried to engage with Yuri over his discoveries. ‘The eye-leaves feature is fascinating, yes. Convergent evolution in action. Of course there must be eyes; eyes developed many times independently on Earth, with no fewer than nine separate designs—’

‘Oh, keep the lecture,’ Mardina snarled. ‘You stupid tin box. Who cares about you? Everything you know is useless, valueless, everything you say.’

Yuri sat on the ground and sipped water from his pack. ‘What’s going on? Why are you arguing?’

‘Ask that,’ Mardina said, making a stabbing motion with her knife.

‘A word,’ the ColU said, with a good approximation of a sigh. ‘We are fighting over a single word. Yet a word which encapsulates a fundamental conceptual issue.’

Yuri thought about that. ‘I don’t know what a fundamental conceptual issue is.’

Mardina said, ‘It won’t have me calling this shack of ours a wuundu. Even though that’s what the bloody thing is.’

‘But the word is inappropriate,’ the ColU said patiently. ‘Because, as I understand it, the word means “shelter”, in the sense of something temporary. This is not temporary. This is not a shelter. It is a house. It is your home.’

‘Of course it’s temporary. Everything here is temporary.’

Yuri thought he understood. ‘You’re talking about the pickup. Everything is temporary, because all we have to do is survive until the pickup by ISF.’

Mardina shrugged, glaring down at her potatoes.

‘There will be no pickup,’ the ColU said. ‘Not soon. Not ever. You heard what Major McGregor said. There will be no return of the Ad Astra, no follow-up expedition.’

‘I can’t accept that,’ Mardina said simply. ‘Look around. Everybody’s dead, except us. We fucked up, collectively; we killed each other off, all but. You can’t build a colony out of two people, no matter how many kids I have with this scrawny refugee, how many of our little muda-mudas end up running around. I know the ISF. They might deny they’re watching us, but . . . There’ll be a pickup. We won’t be left here to die.’

‘You are simply wrong in the premises of your argument,’ the ColU said patiently. ‘The two of you do have significant genetic diversity to found a colony.’

Mardina seemed outraged. ‘What the hell are you talking about? Adam and Eve was a myth, you joker.’

‘No. In the literature there is a case of a camel drover who came to Australia from the Punjab, called “the Afghan”. He took an Aboriginal woman for his wife, and they went into the outback . . . In the end he sired children even by his own granddaughter. And six of eight of the great-grandchildren survived. More recently there has been a remarkably similar case on Mars, where—’

Mardina looked as if she was about to explode. ‘That’s monstrous. And besides I was briefed on the anthropology stuff. I would have heard about this.’

‘Not all of it. Among the crew you were a priority type, genetically. A reserve colonist, so to speak. It was thought best to limit your briefing, no doubt. Lieutenant Jones, the Aboriginal population was isolated from the rest for tens of thousands of years, and so the two of you are about as genetically diverse from each other as two humans could possibly be. In fact, if this situation had been devised for an optimal outcome, it could not have been more—’

‘I don’t care about the genetics. This is like one of those horror stories you read, about fathers locking up their daughters in basements as sex slaves. And now you’re telling me it’s UN policy?’

The ColU said solemnly, ‘The UN is locked in rivalry with China. Proxima must be taken before the Chinese get here. This is the only way to do it. You are soldiers in an as yet undeclared war. So will your children be.’

Mardina stood, brushed dirt from her legs, and picked up the pan of potatoes. ‘This isn’t going to happen, ColU. To hell with you. I am going to wait for the pickup, and if I die before it gets here, well then, I will die childless.’ She stuck her knife into the door jamb of the building. ‘And this is a wuundu, so get used to it.’ She walked away, carrying her pan.

CHAPTER 26

2165

Angelia 5941 woke up with numbers rattling in her head. All around her, the sisters were stirring.

This was the last waking. They would not sleep again, not until Proxima Centauri was reached. And the deceleration routines had now been uploaded to her. At last, Angelia 5941 fully understood the process; they all did. The numbers were brutal. A final betrayal by Dr Kalinski.

Soon the ship would be as close to Proxima as it had been distant from the sun, after its initial four days of acceleration had been completed: about a hundred and thirty times as far as Earth was from the sun. The craft would have to be decelerated for another four days, to be brought safely to rest in the Proxima system. But this time there was no welcoming microwave-laser station to push them back, no Dr Kalinski coordinating the event, no well-trained controllers to guide them home. All there was in the target system was Proxima, and its light. And Angelia was going to have to use the energies of that light to slow down.

The idea was simple. One by one the sisters would peel away. They would form up in vast arrays of lenses, and focus the light of Proxima on the remnant core ship. Just as Dr Kalinski’s microwaves had pushed Angelia out of the solar system, so the visible-light photons of Proxima would slow her down from her interstellar cruise.

But Angelia was travelling terribly quickly, and the light of Proxima was feeble; Proxima was a red dwarf star with only a hundredth the luminosity of the sun. As the implications of the final software download percolated through the sisters’ minds, so the lethal statistics had soon become clear. To slow the remainder at thirty-six gravities, great throngs of sisters would have to be cast off in the first waves, where the mass to be slowed was greatest and the distance to Proxima was at its longest, to effect the deceleration. More than a hundred thousand sisters would have to go, in the first moments alone. As the remnant core slowed, so the castaways would quickly recede from the ship, still sending back their light, until they had gone too far to be useful. Then the next wave would be released, and the next.