‘Sometimes, I’m stopped cold by the thought that one of the girls could grow up to be like Mum. I might end up being afraid of my own child. At other times, I imagine what a relief it would be if my children turned out to have any other problem at all but schizophrenia. I feel as though I might be able to make some kind of deal with God.’

‘You don’t believe in God,’ said Ben.

‘No, I don’t. But it doesn’t stop me. It’s the idea of a bargain, playing with the percentages. I go over and over the figures in my head. Chances are, I say to myself, both the girls will be fine. And genes aren’t the only factor. Schizophrenia is only about seventy per cent inherited – which means thirty per cent is due to environmental factors, right?’

‘Yes.’

‘So if we knew what other factors could influence people . . . If we knew, we might be able to create a different environment, so the genetic switch wouldn’t be flipped.’

‘Matt, you’re making far too much of this. You said yourself most of what you find on the internet is rubbish.’

‘“Crap”, I said. A steaming pile of cow flop, if you like. But not this. You know this isn’t rubbish, Ben.’

‘You’re worrying about nothing. Your children are perfectly OK.’

Ben’s attention was caught by a movement outside. The window looked out on to the narrow front garden and the farmyard beyond. His youngest niece, Josie, was sitting on the dividing wall.

‘That’s what I’m worrying about,’ said Matt.

Ben tapped on the window so that Josie looked up, and he waved. She giggled, waved back, then blew him a kiss.

‘There is absolutely nothing wrong with Josie,’ he said. ‘Or Amy, for that matter.’

‘Do you remember before she started school, Josie had an imaginary friend? She used to say her friend was with her, and talked to her all the time.’

‘For God’s sake, every child has an imaginary friend at that age, Matt.’

‘I didn’t.’

‘That’s because you had no imagination.’

‘Thanks.’

Turning back to the window, Ben saw Josie poke her tongue out at him, perhaps because she’d lost his attention for a moment.

‘Does she still have that imaginary friend?’ he asked.

‘I don’t know,’ said Matt. ‘Josie doesn’t mention her any more, not since she started school. But that might be because she realized other people found it odd, so she stopped talking about it.’

‘Or it might be because she has real friends now and doesn’t need the imaginary one.’

‘Do you think so, Ben?’

‘With the best will in the world, it was a bit lonely up here for Josie when Amy was already at school and she wasn’t.’