He and Mardina, alone together, got along all right. On the whole. In a sense.

For now they had plenty of supplies, so there was no conflict about that. They were calm enough when they discussed common projects, like building the house. They were usually civil, at least, just as they had been before Synge’s killing spree. They may or may not have been the strongest personalities in the original group, Yuri reflected, but they had been among the most self-contained. They’d had no reason to come into collision while everybody else was still around, and they mostly managed to avoid that now it was just the two of them.

They didn’t talk much about the past, those who had killed and died. Even when they did, Mardina never spoke their names. John Synge became ‘the lawyer’, Matt was ‘the artist’, Lemmy was ‘your little chum from Mars’.

And though they kept up their clocks and calendars, Mardina slaving to Earth time, Yuri cross-checking with his amateur astronomy observations, Mardina seemed to mark time mostly by events: the day the lawyer went crazy, the day the ex-cop took up with the artist, the day they were stranded on Per Ardua in the first place. Since Synge’s killing spree a lot less had happened in their little settlement. Two people, it seemed, didn’t generate much in the way of incidents. But even so there were some meaningful events: the day of the bumper potato crop, the day of the big electric storm, the day the ColU threw a tyre on the way back from the Puddle.

Yuri didn’t know what all this meant. Maybe she was reaching back to deeper roots, her childhood. Maybe this was how her own people thought and behaved: maybe they never named the dead, maybe they kept track of time by events, not by counting the days. Yuri didn’t know, he didn’t discuss it with Mardina. Yuri had never been to Australia, back in his pre-cryo life on Earth. And besides, the dried-out, emptied, China-dominated Australia of her age was no doubt utterly different from his own time.

As for the future, they never discussed it, beyond the immediate horizon of their chores. Never, despite the gentle prompting of the ColU. Never, save for the one event that swam in Mardina’s imagination, cut loose from time: the day of pickup, when ISF, she continued to believe, would atone for its crimes by swooping down from the sky to rescue her.

CHAPTER 24

Yuri started noticing problems with the heap of fallen stems he had been retrieving from the lake for the walls and the thatch.

It kept shrinking.

They didn’t alternate watches, as had been the practice in the colony’s early days. The two of them kept to the same day-night sleep cycle, trusting to the ColU to keep watch over the camp while they slept in their separate tents. And it was during the ‘nights’, their sleep periods, that the heap of stems seemed to be diminishing, sometimes to two-thirds, even half the size Yuri remembered from the day before. It took a couple of simple images on his slate to prove he wasn’t imagining it.

The ColU denied all knowledge, though it accepted that the solo patrols it ran during the night around the camp, which was now spreading as the ColU created more areas of terrestrial-compatible soil, meant that it couldn’t watch the stem heaps constantly.

Somebody like Lemmy might have been playing some kind of trick. Not Mardina. Nowadays she walked around in a kind of waking dream, it seemed to Yuri. She barely noticed him most of the time, and she certainly wouldn’t fix on him long enough to figure out an elaborate practical joke.

In the end Yuri spent a sleepless ‘night’ hidden in a storage tent, peering out at his stem heap.

And, in the small hours by Yuri’s body clock, and with the ColU on the far side of the colony inspecting a field of fresh-cropped potatoes, they came. Builders. They kept to the shadows of the tents, whirling, rustling things like low stools or tripods, stick limbs attached flexibly to a central core of tangled stems. Builders, from the Puddle! He counted two, four, eight, nine of them: nine, he thought, three threes, a logical number for creatures with threefold symmetry. They made for the stem heap, but paused frequently, apparently listening, or watching.

When they got to the stems, after maybe a minute of stillness, the builders started buzzing around the heap, plucking out stems with their fine ‘limbs’ of multiply jointed rods and gathering them into loose bundles. Yuri marvelled at the way they worked together, graceful, cooperative, creatures of jointed twigs moving with no more noise than a dry rustle, a sound like a sack full of autumn leaves gently shaken. And he realised they were being pretty smart; whatever they wanted the stems for, this was a pretty good moment to come and get them, in the middle of Yuri’s and Mardina’s sleep cycle, and with the ColU far away. Evidence of observation, of planning.

But they were robbing his stash.

He burst out of hiding. He had a saucepan and lid that he clattered together, making as much noise as he could as he ran at them. ‘Get out of here, you little bastards!’

The builders froze, just for an instant. Then they scooted off, rolling in their tripod way, much faster than Yuri could give chase. They carried off most of the stems they had stolen, though they dropped a few, leaving a trail of broken stems that led straight back to the lake.

He didn’t sleep again that shift.

When Mardina emerged from her tent, barefoot, hair a tangle, he tried to show her the heap, the trail of stems.

‘I’m going out after them. We need to know more about those little sods.’

‘Suit yourself.’ She filled a pan from the small tank they kept topped up with filtered lake water, and carried it to the fire to boil up.

He followed her. ‘I thought I would have disturbed you in the night. All that jumping and hollering and lid-banging. Even the builders made some noise.’

She shrugged, without reply. She was inspecting one of their packs of freeze-dried coffee, precious stuff and irreplaceable; the pack was almost empty, but she shook out enough dust for one more cup.

‘You know,’ said Yuri, frustrated, ‘I sometimes feel like you’re barely aware that I’m here at all. Like I’m a ghost.’

She looked at him directly for the first time that morning. ‘Maybe you are. Maybe I’m a ghost too.’ She pulled a face. ‘Maybe the lawyer got us both, and it happened so quick we don’t know we’re dead. Maybe there’s nobody here on Per Ardua but us ghosts. You, me, and Dexter Cole.’

He turned away. She was just jabbing at him, but she had learned how to get under his skin. He wasn’t superstitious, he didn’t think, but sometimes the sheer emptiness of this world got to him, and she knew it. ‘I’m going after the builders,’ he said doggedly.

‘What about the wuundu?’ Which was her word for the house; the ColU didn’t like her using it.

‘A day off won’t hurt.’

‘What’s the point? We’ve still got plenty of stems.’

‘I’m curious, that’s all.’

‘Fine. Go off and be curious. I’m going back to bed.’ Her pan of water had boiled; she poured it carefully into her coffee.

So Yuri put together a quick pack, food, water, a couple of knives, his slate, rain cape, fold-up sun parasol – and, when he thought it over, a crossbow – and set off.

The trail left by the fleeing builders was easy enough to track at first, a litter of broken stem fragments. It headed north, towards the Puddle.

The sky was clear, and the heat of Proxima poured down. The ground was a plain, more or less flat save for occasional outcrops of rock, bluffs of what looked liked sandstone to him, none of them approaching the size of the Cowpat. He remembered McGregor saying this site had been chosen as a shuttle landing site in the first place because it was the bed of a larger dried-up lake, and it certainly felt like that now.