‘If I said bums in front of a kid at work it wouldn’t be the end of the world. It’s arguably their favourite word. So I can allow myself that from time to time.’

‘Allow yourself a bum from time to time. Quite right,’ says Gus, and I want to cry. I’m going to miss them so much.

I meet Troy on the corner and we talk bravely about how much better our new life in France is going to be, about how we’ll have baguettes and croissants and snails.

‘I probably won’t come back,’ he says, and he spins a fantasy about living in a Parisian attic with a beautiful woman and discovering his talent as an artist. I’m sure I’ve heard it before, but I go along with it, asking questions, stretching it out all the way to school.

We pick up other people as we go, and I look at all of them, knowing that they will be adults and I won’t, that they’ll tell new people, ‘When I was at school one of my friends disappeared.’

I’m going to see them tomorrow too. And again and again and again. Every single day until the end of time.

I look at Jemima and she grins back at me. I know she’s really pretty and that I used to have the most massive crush on her, but I don’t feel anything. I remember an intense friendship with Marco that went somewhere unexpected, but I don’t really remember that either. I realize I have no idea whether I like girls or boys, or a bit of both, because the only person I have any feelings for is Ariel, and it’s not so much that I fancy her. I did, when I thought we were both real, and of course I still do, but it’s been complicated by the facts.

I remember that I’m supposed to be gathering information for her, and let Lucas walk with me, so I can work out how much he hates me. We don’t really get on, but it’s quite a leap to think of him killing me later today.

Lucas is just a bit of an oddball, I think. He’s huge and seems much older than the rest of us (though I’m thirty-five, so I beat everyone). He makes me feel uncomfortable, which I guess makes him a suspect.

‘Hey,’ I say.

‘All right, Joseph?’ he says. He gives a stupid grin. ‘Comment ça va?’

I ignore the French.

‘Lucas?’ I say. ‘Would you murder me if you could definitely get away with it?’

He gives me a weird look. ‘Why would I want to murder you?’

‘Is that a no?’

He frowns and walks off.

As soon as I get into the tutor room I start recording our conversation in my notebook.