‘Don’t you know how many things can go wrong?’ she was saying now, turning to the science just like her mum had taught her – and somewhere she had lost her temper with this stubborn, arrogant old woman – ‘Can’t you see how much you don’t know? How dangerous it is?’

Had the whole carriage gone quiet?

‘Have you any idea how many generations it might take to even reveal the dangers? The long-term effects?’

She was aware of a movement beside her, but she ignored it – she wouldn’t listen to more of Piotr’s statistics now. God, the man was a buffoon. There was something important in what she was saying. She was working something out …

‘Will we lose the ability to reproduce altogether? Become completely dependent on technology outside of ourselves? Will we cease to be … Oh my God. It’s genetic. That’s why it’s showing in the third generation, that’s why James was so terrified. We’re inheriting a new type of infertility, a predisposition to miscarry, developing it in the pouch and passing it on to our children – an inability to be born, like the babies’ bodies are rejecting the process, preventing it – it’s there already, in everyone born via the pouch, so we can’t … the damage is done. We might never be able to fix it.’

She turned towards Piotr. He’d thought about it too, she realised, he had been thinking about it here, on this train, and so he must have the same question.

‘Our baby …?’ she said, needing him to look at her now.

But Piotr was leaning over the table. Piotr was taking Holly’s hand in his – no, Holly’s hand was lying flat on the table, palm down, he was placing his hand over hers, he was offering comfort. Eva looked at him in disbelief, in anger – he was taking sides. He was taking sides? No, he wasn’t taking sides. He was reaching for her hand too. He was holding both of their hands over the table. Hers and Holly’s. And she felt, at last, all the ways that they were the same. Holly’s eyes looked blurry. She looked old, not arrogant, she looked sad and lost, staring at her the way Eva had once stared out of a window with no words to describe how lost she felt. It is terrible, the way what you believe in can let you down with such devastation.

She felt suddenly ashamed. But as she looked at Piotr, as she noticed that her arm was leaning against his and that there was a familiarity about his skin, about his smell, she realised that somewhere between losing her and not quite losing himself, Piotr, whom she had once loved, whose hand was gently resting over hers, had become kind.