‘What’s behind it?’ I say. I’m afraid. Very afraid. A wave of terror crashes in the place where my stomach would be, if I had one.

‘Just before you got here,’ says Troy, ‘we found – well, we found your schoolbag. And this was on top of it.’

He reaches down and picks something up very gingerly, holding it by the edges. I look down.

‘The football trophy,’ I say. We all stare at it. There it is at last. The foot kicking the ball. The real one, the one that’s in my bag.

‘Tell us about the angry man,’ says Ariel. ‘We don’t have much time. He followed you in here?’

I make myself calm down. Forget the trophy. Yes. The angry man.

The trophy, though.

‘He did. I was extra rude to him. I took his photo, right in his face. He came after me and said he was going to take the camera and that I had to buy him new shoes. But he didn’t take it. He didn’t do anything. He just stormed off.’

‘It’s not time yet,’ says Troy.

‘That’s true,’ says Ariel. ‘He might come back. Can we see the photo?’

I get out Gus’s camera and switch it on. Its small screen is nothing like the tech from the future, but all the same I got some good shots. He’s staring right at the lens, face contorted in fury.

I hold it out.

‘Here he is,’ I say. ‘See how lovely he is? Ariel and Troy, meet the angry guy.’

Troy leans in and looks at it. He tries to touch it, to bring it closer, but finds he can’t.

‘He seems nice,’ he says. ‘Don’t recognize him, though. Sorry.’

Ariel looks.

She leans forward and looks again.

‘Oh,’ she says.

‘What?’ I say.

‘Ariel?’ says Troy.

Ariel doesn’t look at either of us. She just carries on staring at the screen. Then she stands up, walks over to a wall and leans her forehead on it. She goes to the part of wall they’ve taken apart in their world and looks into it. I don’t know what’s wrong. Troy and I exchange glances. Neither of us has the faintest idea of what is going on with her. She has her arms up round her face and her back is shaking.

‘Ariel?’ I say it this time. I look at her back. She’s kind of leaning right into the wall. It looks extremely weird. It’s proper ghost behaviour.

Then she leaps back.

‘Oh my God!’ she says. ‘Oh shit!’

Troy and I both jump up. I try to put an arm round her shoulders, but I can’t. Troy can and for a fraction of a second I hate him.

‘Ariel?’ he says. ‘What? Tell us what’s happening.’

I watch her force herself back under control.