She spotted a crocodile of schoolchildren, evidently visiting the area, walking in pairs hand in hand, boys and girls in bright green uniforms: green, of course, for visibility on Mars, with its palette of rusty red and brown. They stared openly at Penny – there were few Western faces to be seen here – and she took care to smile back.

She said, ‘I’d be interested in a discussion on the nature of freedom here before I leave.’

‘I would enjoy that.’

CHAPTER 52

2193

Beth, Freddie and some of the other youngsters loaded backpacks and set off west to attempt a circumnavigation of the lake.

The rest pitched camp in their practised fashion, laying down hearths, digging out storm shelters and latrine trenches, erecting their tepees and houses. The trucks, released from the ColU’s direct control for these simple tasks, got to work ploughing up yet another stretch of Arduan ground, digging out fields extensive enough to raise a quick crop.

The ColU itself, meanwhile, rolled down to the lake, where there were wide stem beds, and communities of builders with their usual nurseries, middens, dams, weirs and traps. It was almost like the builder projects around the jilla lake, Yuri thought. But there was no evidence that these builders were making any effort to manage this lake as a whole. The ColU watched the builders patiently, inspecting their structures, even communicating with them with its manipulator-arm hand-puppet builder talk.

When Beth and the rest returned from the lake, Mardina gave them a camp night off to recover, feed, wash. Then she called a council of war.

The core group were Mardina, Yuri, Delga, Liu Tao, Mattock. They gathered around a hearth, unlit but with its base slabs of basaltic rocks still hot enough to warm a pan of nettle tea. Other adults gathered close by to listen, a dozen or so, dozing, doing chores, with kids running around at their feet. The rest stayed away, working, napping in the heat. The ColU rolled up too, silent, massive, its hull and manipulator arms grimy from the soil it had been working.

At last Beth and Freddie showed up, all but naked save for strips of stem-bark cloth at breasts and groin, and well-worn bark sandals on their feet.

Beth gracefully helped herself to a mug of tea. She was twenty years old now, and as she moved Yuri noticed how the men in the group reacted to her slim grace. Her tattoos showed up on her dark, sweat-streaked skin: on her face was etched a mask something like Delga’s but less severe, more stylised, and there was a kind of sunburst design on her back, a Proxima-like star poised over an upturned human face. She had had almighty battles with her mother about getting these done; Mardina the ex-astronaut associated tattoos with gangs and drugs and criminality. But most of the kids, especially those from the mothers’ group who had started the fashion, wore tattoos of one kind or another. It was about the only kind of art they could practise, and for sure the only kind they could carry as the group continued its endless migration. Yuri had stayed out of the argument. Delga, poster model of the tattooed crowd, had just laughed.

‘So,’ Yuri said, prompting Beth. ‘You’re back earlier than you thought.’

‘Yeah.’ Beth sat on her haunches, sipped her tea, and glanced around the group, confident in herself. ‘You know we hoped to go all the way round the lake. We started on the north side, and went west and skirted that shore, and came to the southern shore. Then we came to a river we couldn’t cross, a heavy flow that comes down from the higher ground to the south.’

Freddie said, ‘The river water pushes right out into the lake. You could see the mix of colours, the mud it raised.’

‘OK,’ Mardina said. ‘And can you get any further south?’

Beth said, ‘You could follow the river valley. But it looks like it gets pretty narrow, and there’s a steep climb.’ She grinned at Yuri. ‘Dad, there’s a waterfall! You should see it. And beyond that the ground just rises up, and there’s a sort of forest. Not like the trees at home.’ By which she meant the place she had been born, near the stately forests of the far north. ‘These are short, lots of branches, rattled around by the wind. It’s hot and steamy. I can’t imagine us ever clearing it, and living there. But . . .’

‘Yes?’

She grinned. ‘We saw more tyre tracks. Heading off south into that jungle.’

Mardina murmured, ‘There has to be some kind of base in there. A technologically advanced base, sitting at this pivotal point on the planet, while the rest of us scrabble in the dirt.’ She glanced at the cloud-covered sky. ‘ISF. Presumably resupplied from orbit. Maybe even relieved by the return of the Ad Astra, or some other ship. Christ. I was right all along. They never did leave.’

Delga said, ‘Well, we’re going in to see. Right?’

The ColU said, ‘If I may speak, Lieutenant Jones—’

Mardina said, ‘When have I ever been able to stop you?’

‘There is another reason to go into the Hub.’

Yuri said, ‘ “The Hub”, ColU?’

‘Forgive me. That is the local builders’ term for the substellar point. Probably a term used across the planet, in fact. “Hub” being my translation of a term that also refers to the cylindrical core of their stem bodies.’

Delga snorted. ‘You’ve been talking to those spindly little jokers again. What a waste of time.’

‘I cannot agree,’ said the ColU precisely. ‘I learn a great deal whenever I meet a new community. Their language is very ancient, quite static; their culture is locally variable, but there are many universals. Such as the concept of the Hub. This is my interpretation of a complex idea . . . To the builders, the substellar point is the centre of the world, a pivotal place. Yet it is a lost place. It is their Garden, Lieutenant Jones. That is where they lived before they Fell, they believe. It is the centre of their consciousness. Much of this is a very old apprehension. Memories deep and old, like relics of animal ancestries. You humans have the trees, from which your ancestors once descended. The builders have the Hub.

‘Yet there is a newer layer of meaning. These local builders seem to speak of recent events. They did return to the Hub, I mean in living memory – why, I am not certain, but surely to perform some task. That is what builders do. They worked here. But now they are excluded.’

‘By the ISF team in there,’ Mardina said grimly.

‘Presumably.’

Liu Tao said, ‘What concerns me is how we’re going to live here.’ Since leaving the confluence Liu had taken a young wife, a daughter of Dorothy Wynn, who had given him a child, a daughter called Thursday October – named that way for her Earth-calendar birthday. Yuri had seen how Liu’s priorities had changed dramatically once the kid had arrived. ‘Whatever we do about the ISF and the Hub, let’s get it done, so we can get out of here.’

‘I would agree,’ the ColU said. ‘The star winter won’t last for ever. I have in fact been making this point for some time.’

‘We know you have,’ said Yuri.

‘When normal temperatures return, this region will become uninhabitable—’

‘We know.’ Mardina looked at Yuri, Delga – even Mattock the former Peacekeeper, who was scowling furiously at the idea of some kind of well-equipped ISF base on this planet, from which he was obviously excluded too. ‘We’ll go back north,’ Mardina said. ‘But not before we go and see what’s in this jungle. We’ve come this far. Anybody object violently to that?’ There was no reply. Mardina stood up. ‘OK. We’ll take the trucks, or at least one of them. Beth, Freddie, you scouted it out. Work out a route, a way in. Yuri, you can work with the ColU on how to manage the trucks. We’ll take our time. Get ready properly. Then we go in,’ she said evenly.