‘That would take a heck of a lot of delta-vee.’

‘Yes. But then you could break it up slowly, drop the material you need into the air, with Ceres itself as a construction shack.’

Penny nodded. ‘I do know there was evidence on Earth, our Earth, of major climate disturbances caused by impacts of comets or asteroids. Fifty-five million years back, a spike in the carbon dioxide levels – doubled in a single year. So the idea is not implausible.’

Ari listened carefully, picking through the technical language. ‘Hairy stars and the Tears of Ymir, falling to Terra – and now to Mars. So do you think Earthshine is sincere? Perhaps we should be wary. He is proposing to deploy large energies, to move huge masses around the planetary system – our planetary system.’ He grimaced. ‘If he is allowed to wield such energies, your artificial man would be as powerful as a god.’

Penny said, ‘So he was before, in our reality. But here’s what you have to understand, Ari. Earthshine and his brothers, the Core AIs, were significant powers on our Earth. But, like gods, they always had their own agenda. An agenda that might or might not coincide with the interests of mankind … And whatever Earthshine says about Höd now, we’ll have to remember that here too his own deep agenda comes first.’

‘Very well. And what might that “deep agenda” now be?’

‘We’ve no way of knowing.’

‘I recall the talk of your “impossible sister”, Penelope Kalinski. Earthshine was fascinated by that. You’ve said so yourself. Earthshine detected this – unravelling of history – before he and you witnessed it on a much larger scale. Prescient, don’t you think? Wouldn’t he pursue such an interest here?’

Sure he would, she thought. It was odd to think that even now she and the rest of the Tatania crew were still dependent on Earthshine, for the translator gadgets he had provided them all with, and regularly downloaded updates of vocabulary and grammar. And she did remember how obsessive he had seemed about the interference in human history by an agency unknown, right back to the beginning of her own involvement with him, going back more than three decades of her complicated life: I am everywhere. And I am starting to hear your footsteps, you Hatch-makers. I can hear the grass grow. And I can hear you …

Ari said acutely, ‘I find myself deeply drawn to the question, in fact. Might there be evidence to be unturned concerning these strange phenomena in my world? Traces of lost histories. Like the anomalous carving on the tombstone of your mother, Penny, in that graveyard in Lutetia Parisiorum of which you spoke.’

His mention of that personal memory startled Penny. She had been open with Ari, mostly, about her experience of the reality-shifting they had all endured. Now she wondered if that had been wise, if she understood Ari and his agendas. She was aware that Marie, too, was looking increasingly wary.

‘So have you found anything?’

‘Not yet. But I’ll keep looking.’ He stared into her eyes. ‘That makes you uncomfortable. Why?’ When there was no reply he went on, ‘I sometimes think you are fortunate that we Brikanti are not more curious about this phenomenon. We are not so scientific as you.’ He pronounced the English word carefully. ‘We are cruder philosophers. Perhaps we are more prepared to accept the miraculous, the unexplained, than you are. Unexplained phenomena such as your own existence. We don’t question; we just accept.’

‘All save you.’

‘All save me. But why are you wary of the question?’ He turned on Marie. ‘And why do you recoil as we speak of these matters, Marie Golvin?’

‘Because I can’t sleep,’ Marie blurted. ‘That’s why. Is it so hard to understand?’ Penny covered her hand with her own, but Marie pulled away. ‘Look – we saw billions put to the torch – everybody we knew, probably, whole worlds, Earth itself. And now here I am in this stupid place, trying to learn your dumb languages, doing this makework job you’ve given me, and pretending I’ve got a future here. I don’t even know if your Jesus died for me, or not.’

On the verge of tears, she seemed much younger than her twenty-seven years, and Penny longed to hug her, to reassure her. But Marie Golvin was an ISF officer, and that wouldn’t do at all.

‘I’m sorry,’ said Marie now, getting herself under control. ‘Excuse me.’ She stood and walked away.

‘And I too am sorry,’ Ari said to Penny. ‘For provoking that.’

‘Not your fault,’ Penny snapped. ‘Well, not entirely. You do keep prying.’

‘You’re lucky that others don’t.’

‘Maybe, but that doesn’t help. It’s survivor guilt, Ari. It’s when you forget it all – when you are immersed in something, happy in yourself, enjoying what you’re doing – and then you remember all that has been lost, and the guilt comes crashing down again. That’s when it’s worst. Marie’s particularly vulnerable now she’s away from the protection of Lex McGregor. The ISF, the military discipline, was her whole life. And then there’s the hope.’

‘Hope?’

‘Of somehow, one day, finding a way back home, back to our timeline.’

‘Ah.’

‘It’s entirely irrational, I think we all know that, but it’s hard not to succumb. After all this can never be home, for us. And it’s harder for the young, I think. As the years go by.’

Ari said, ‘But Marie told me she was a Christian, in the tradition as it existed in your world. Just now she spoke of Jesu – Jesus. Should that not be a consolation? She says she wondered if, in crossing realities, she had undergone something like the Rapture. Are you aware of that?’ He closed his eyes, remembering. ‘The text she recited to me was this: “For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord. Wherefore comfort one another with these words.” From a letter to the Thessalonians. Such material does not exist in our Bible, not the authorised version, and nor does the legend of the Rapture. I think, you see, that Marie fears not that she has been taken up to heaven by God, but has been left behind in the desolation that remains—’

‘You.’

Beth Eden Jones came stalking into the refectory, trailed by an anxious-looking Marie Golvin.

CHAPTER 17

Ari and Penny stood to meet her.

Beth was wearing Brikanti costume, as they all were after two years here, tunic, trousers, leather boots, a light cloak. Though she looked heavy, she was evidently no longer pregnant, Penny saw immediately. And in her arms she cradled a bundle wrapped in blankets.

Penny said, ‘Beth? What the hell – is that what I think it is? You’ve had your baby? I’m sorry – I lost track of the date, I didn’t hear any news …’

Ari stood silently, his face like thunder.

Beth stood before her husband, glaring at him, but she spoke to Penny. ‘Yes, Penny, this is my baby. By this monster.’

Ari stared back. He said in a kind of growl, ‘Not here, woman. Not now.’

‘Then where, if not before my friends? Shall I go back to your home, your family, and wait until the next time you try to kill her?’

Heads turned around the refectory.

Penny said sharply, ‘Beth. Whatever the hell you’re talking about – come on, sit down.’ She put her arm around Beth’s shoulder, and could feel her trembling, could see the stain of tears around her eyes. She looked a lot older than her thirty-eight years, old and drained. But she complied, sitting at the table which still bore the remains of their meal. Penny said, ‘You too, Ari, don’t loom over her like that. Beth, do you want anything? A drink—’

‘Nothing.’ Beth’s and Ari’s eyes were locked still.