Clara dimmed the lights so that they could see out more easily, but once the hills by the roadside had dropped from view there was nothing in sight from their present vantage but the unchanging sky.

‘You can get up now if you like,’ Clara announced, unstrapping herself and rising to her feet. Eusebio did the same, then Valeria joined them by the window. The dark ground was receding rapidly; she could already see the lights of the city. But their motion was so smooth that it felt more like the product of ropes and pulleys than any kind of rocket.

Valeria said, ‘I’m sorry I doubted you. I’m sorry for what we’ve put you through.’

‘It’s all right,’ Clara assured her. The traveller put an arm around her shoulders.

‘Yalda’s really dead,’ Valeria said. ‘Years ago. Generations ago.’

‘Yes. But she had four wonderful children in the flesh, and in spirit you could call her the mother of us all.’

Eusebio leant against the window, covering his eyes.

Valeria composed herself. ‘When can we meet everyone? When are they coming to Zeugma?’

Clara said, ‘There’ll be other emissaries soon. Once I’ve reported back.’

‘But the Peerless—?’

‘The mountain itself won’t come down to the surface. People will be welcome to visit it, but most of the travellers won’t be settling on the home world.’

Valeria was astonished. ‘They’re going to stay inside?’

‘Some will,’ Clara replied. ‘It’s what they’re used to. Some might settle on the sun, opposite the engines, if it proves safe there.’

Valeria gazed down at the crevasse that divided Zeugma; from this height, in the starlight, it looked like a faint scratch.

‘Tell me about your family,’ she begged Clara. ‘Your father, your brother and sister, your co.’

Clara hesitated. ‘I don’t have that kind of family.’

‘They all died?’ Valeria was horrified.

‘No, no! Of course not.’

‘So . . . you’re a solo?’ With no father, so her mother must have fissioned spontaneously, like Valeria’s mother Tullia. ‘But you didn’t even have a brother and sister?’

Clara said, ‘Most of us have just one child. My mother shed me; I shed my daughter.’

Valeria understood. She felt a slight giddiness at the implications, then it gave way to a glorious sense of a new world spreading out beneath her gaze.

Eusebio turned from the window. ‘And who has the sons?’

Clara thought for a moment. ‘I said mother and daughter, but they’re not the right words. We tried very hard to live as men and women, but we couldn’t make that work, so we folded the two into one. My “mother” raised me as a father would, as I raised my own “daughter”.’

‘So you’ve wiped out all the men?’ Eusebio asked numbly.