‘Ten, when it started. I was small for ten, and skinny, which helped.’

The matter-of-fact way he says it chills me more: there’s no self-pity at all. ‘How many times did your dad do this?’

‘Three. He told me after the first time, when we did a runner to a different part of the country. After that, it was less scary, because even when he was telling everyone I was really sick, I knew I would be OK. Though I hated him lying to all these people who were trying to be kind. I mostly kept quiet, but sometimes . . . well, sometimes I had to lie too, because Dad said he could go to prison otherwise.’

I can’t quite believe what he’s telling me. Yet at the same time it makes sense, in a warped way. ‘How did he get caught?’

‘We were packing up to move on again when they arrested him. A journalist on the local paper got suspicious. These days you’d be rumbled straight away, with the internet, but the nineties was a golden age for con men.’ Dan’s voice drips with irony, and his handsome face is almost defiant.

But I don’t only see him as he is now; I also see a skinny boy whose father used him as a prop. What parent would tempt fate by pretending their child was dying?

And I remember that morning we met, when he was scared to go into the hospital. Now I understand.

‘That’s why you hate anything medical?’

He nods, shamefaced. ‘Even though I’ve never had anything worse than a cold. Unlike poor Casey.’

‘So when she got in touch and said she was sick . . .’

‘Felt like karma. That she was being punished for what me and Dad did.’

‘Except you were the one who stopped your father doing it again?’

‘I grassed him up. The police and the social workers talked me into it. Made me think I had no choice but to betray him.’ His voice is monotone, as though he can’t let himself feel the emotions behind the memories.

‘Dan, listen to me. You didn’t betray your father. He betrayed you.’

Dan scoffs. ‘You don’t understand. In our world, grassing someone up is the worst thing you can do.’

‘Worse than scaring your son into thinking he was going to die? I can’t believe someone would do that to a child. It’s incomprehensible.’

How do you recover from something like that? Everything I take for granted in my family – love, nurturing, loyalty – has been twisted in Dan’s. Yet despite that, he’s tried hard to make amends through his work with young offenders, and the way he’s tried to get to know Casey.

‘I promise I’m not lying now,’ Dan says softly.

‘I know you’re not. But your dad’s actions are unforgivable.’

‘He didn’t have it easy. He had to raise a kid alone, one who reminded him of the wife who’d died in labour. Then if that wasn’t bad enough, I switched sides. No wonder he hated me.’