The humans walked through, one by one, led by Beth. Mardina brought up the rear. Yuri looked at his group. Beth was full of wonder. Tollemache, heavy in his ice coat in a room that seemed distinctly cooler than the world outside, seemed greedy for discovery. Mardina remained the most cautious, yet she had come through with the rest.

Yuri grabbed her hand. ‘It’s OK.’

‘Is it?’

‘We’re all together.’

‘It’s just my training, I guess. I keep expecting something to happen—’

‘Mom! The door!’

Yuri turned, too late, to see the hatch behind them swing closed, sealing itself neatly.

‘Like that,’ Mardina said angrily. ‘I keep expecting something like that to happen.’

Yuri’s first reaction, oddly, was to think of the ColU, suddenly shut off.

‘So we’re stuck,’ Tollemache said. ‘We’re fucking stuck.’

‘Don’t swear at me, you ass,’ Mardina said. ‘You could have stayed out there. You could have blocked the hatch.’

‘What with? Your husband’s head?’

‘Well, he’s not my husband. Nice idea however . . .’

Things started happening quickly. The builders had scuttled over to the hatch in the far wall, and were already settling into place in their grooves.

And Beth went back to the previous hatch and ran her hands over its surface. ‘Mom. Dad. Stop arguing. You’re missing it again.’

‘What?’ Yuri snapped.

‘What’s important. Look at these.’

She had found indentations on the inner surface of the closed hatch – not builder profiles this time, but the imprints of human hands, three sets of them.

‘I will swear,’ Tollemache said heavily, ‘on your mother’s grave, ice boy, that those shapes were not there a minute ago.’

Yuri glanced across at the far door where the builders were almost settled in place. ‘But their meaning is obvious, isn’t it?’

‘We do have a way back,’ Mardina said.

‘Yeah. Look, we have a choice. We can go back – if this door works as it looks like it will. Or—’

‘We go on,’ Beth said, grinning. ‘Come on. There’s no real choice, is there?’

Once again they waited until it was too late; once again the choice made itself. The builders settled into their slots, and the second wall hatch swung back, just like the first.

And it felt as if the floor fell away beneath them.

CHAPTER 59

2197

The Obelisk negotiations started late on Penny’s second day on Mars, to allow for the visitors’ misaligned biological clocks.

The talks were held in a panoramic conference room, on a floor of the Obelisk even higher than Penny’s hotel room. The main players sat at a long table, with the UN Deputy Secretary General and the chief Chinese official, a local provincial governor, facing each other across the centre of the table, with translators scattered around. Penny was here purely to advise Sir Michael King, so she sat back from the table just behind him, coming forward only when he beckoned her.

It seemed to Penny that the talks proceeded pretty well, on a broad-brush level. The delegates on both sides set out goals, aspirations, rather than demands or decrees. Visitors from UN nations should be allowed access to the Chinese offworld operations – especially the asteroid Ceres, the hub of development in the main belt, which was currently entirely closed to the UN. Similarly UN zone corporations should be granted licences to begin a share of exploitation of asteroid resources; after all, there was enough for everybody. On the other hand the Chinese wished for some kind of access to the kernels, at least to the wild developments in physics theory they had spawned, if not to the objects themselves. There were no blank refusals on either side, not yet.

Most of the discussion concerned matters of principle rather than details of the kernel science that was Penny’s speciality, and she had plenty of time to kick back and stare out of the window at the view. They were so high up that Mars’s tight horizon visibly curved, as if she was in some aircraft, not in a solid structure at all.

In a break, Penny stood with Sir Michael King and her assigned companion Jiang Youwei at a window, clutching coffees. King agreed that progress had been reasonable. ‘Here you have two societies with competing strategic goals, but with an almost entire lack of understanding of each other. A classic recipe for war, no matter how long we talk about zones of influence and such. But today, war is unthinkable.’

‘Yes,’ Jiang Youwei said seriously. ‘Both sides command enormous energies, the UN with its kernels, the Chinese with our interplanetary economy. Yet the populations of both sides are hugely fragile, we under our domes, the UN nations with their sprawling masses under an open sky—’

‘Not to mention the sprawling masses in China itself,’ King said sternly.

‘Of course.’

‘At the same time,’ King said, ‘we each have a monopoly of something we don’t want the other guy to share. We the kernels, you the asteroids, roughly speaking. So what we’re each doing is prising open our treasure chests and letting each other at least sniff the gold. Everything is symbolic. The very fact that we made the effort to come all the way out here rather than just send a delegation to New Beijing on Earth is itself a token of our willingness to cooperate.’

He was right, of course. It was all about symbols, on a level beneath the torrents of words. Penny understood that as a ‘face’ of kernel physics, internationally known, her presence too was a symbolic gesture. Even if she never opened her mouth.

Jiang said, straight-faced, ‘And of course your immense hulk ship in orbit around Mars is itself another symbol.’

King raised his eyebrows, and mock-toasted the boy’s answer with his coffee.

‘Maybe free trade will be possible some day,’ Penny said. ‘That’s generally a way to avoid war.’

King glanced at Jiang. ‘Maybe. But would your society, here on Mars for instance, be “free” enough for that? What does freedom here actually mean for you?’

Jiang might have taken offence, Penny realised. In the formal talks both sides had shied away from any comment on the other’s political system. But, from what she had seen of the city of Obelisk, she was curious about this herself. ‘We never did have our conversation on that topic.’

Jiang merely nodded thoughtfully. ‘It is an interesting question. We of Chinese descent are products of a stable society now centuries old—’

King snorted disrespectfully. ‘All framed by a value system that goes back to Karl Marx and Chairman Mao.’

‘But within any system, the challenges of ensuring freedom under conditions that pertain in an offworld colony – even here, in the largest offworld colony of all at the present time – are significant.’

‘In our Western tradition the freedom of the individual is paramount.’

‘Yes,’ Jiang said, ‘as I understand from my own school studies. But even in your own offworld colonies the freedom of the individual must be curtailed, if the collective good is to be maintained. The problem is the fragility of the colonies. One cannot challenge the most repressive dictator, if that dictator is the only one who can control the air supply.

‘We have philosophers exploring ways of ensuring individual freedom within a tightly constrained collective system. This is after all the condition under which most of mankind is likely to live for the foreseeable future. We reach back to old traditions; a citizen of the Roman Empire, for example, would have placed less value on individual liberty in the modern Western sense than on collective responsibility – a collective liberty, if you like. Actually it is a system-wide debate, for us. An ongoing participation for all our citizens, on Earth as well as offworld. Though we are not minded to follow your example, as evidenced at your Eden colony on Mars – I have been there myself – of excessive individual freedom kept in check by excessive policing.’