‘I think he was trying to teach me algebra. He kept getting me to mow and repeat random letters and numbers, over and over again – a1, b8, d4, h6 . . .’

‘Oh,’ says Jake. ‘That’s a weird way to teach algebra.’

‘I know, but it must have worked because I can see them all the time – b6, f4, h6 . . . It’s like I’m sinking battleships in my head.’

‘Well, I guess it’s better than sitting in the classroom with Mr Andrews . . . and at least you didn’t have to play chess.’

Rebecca turns around, smiling.

‘What’s wrong with you, Brains?’ asks Jake.

‘You two,’ Rebecca says with a grin. ‘Are you really that dopey?’

‘No!’ me and Jake say at the same time.

‘Well, you must be. Did he get you to mow ranks and files?’

‘Yes, how did you—’

‘And you made squares and gave them letters and numbers?’

‘Yes. I just said that.’

Rebecca puts her hand over her mouth. ‘Oh, Felix,’ she laughs. ‘Can’t you see what he did? Those letters and numbers are the names of the squares on a chessboard.’

‘What?’ I narrow my brow. ‘They can’t be.’

‘If you are playing the white pieces, a1 is the square in the bottom left corner. h8 is the—’

‘. . . Top right.’ My jaw drops open.

Jake facepalms. ‘Oh my god, Felix, you idiot!’

‘Don’t call me that!’

‘But it’s obvious,’ says Jake. ‘It wasn’t algebra. He was teaching you chess all along.’

‘You didn’t know either,’ says Rebecca, sticking up for me, but I’m not sure she should. How could I have been so dopey to fall for it? My granddad has got me playing chess. Chess. Chess!

‘Ah, god!’ I screw up my face. ‘What am I going to do?’

The table shakes as Jake tries to stop himself laughing.

‘It’s not funny, Jake.’

‘Sorry.’ He puts his hand over his mouth.

‘There’s nothing wrong with chess,’ says Rebecca.

‘There’s nothing right with it either,’ says Jake with tears in his eyes. ‘Oh god, Felix, look at you. You look like you’ve seen a ghost!’

‘Leave him alone,’ says Rebecca. ‘You wouldn’t have guessed either.’

‘I would,’ Jake replies. ‘But that doesn’t matter – look at him, he looks like he’s seen a ghost.’ Jake puts his arm around my shoulders. ‘It’s okay, Felix.’ He grips me tightly. ‘We’ll get you out of this.’

‘How? This is a nightmare. I saw squares all night. He’s brainwashing me. Mum was trying to tell me about her yucky romantic weekend away, but then gave me a weird look when I asked for h2 for breakfast.’

Rebecca tries to stop her laugh spilling out. Jake stares into space.