I said, ‘If she was going to kill him, why not do it straight off? What were the extra meetings for?’

‘Working up the guts. Or there’s something she wants to find out, before she decides whether to do it – whether he actually raped Selena, maybe. Or she’s got no plans to kill him, not at first; she’s meeting him for some other reason. And then something happens.’

Selena to Chris, the 8th of May, late at night: I don’t want us to be like this forever. Maybe this is completely stupid but there has to be some way we can be friends. Just hold on to each other till maybe if you’re not too furous with me we can try again someday. I can’t stand us losing each other totally.

Conway said, ‘She’s dying to get back with him. She can talk about just friends all she wants; that’s what she’s after.’

I said, ‘She said she was saved from doing it. This is what she meant. If Chris had texted her back, no way she would’ve stayed hardline about not meeting up. They would’ve been back together inside a couple of weeks. Maybe that’s what Mystery Girl was at: keeping them apart.’

‘If you were a teenage girl,’ Conway said. ‘And you wanted to keep Chris away from Selena, for whatever reason. And you were fairly sure she hadn’t been shagging him. And you knew what Chris was like.’

Silence, and the long red stretch of the corridor, tiles shifting queasily.

‘He brought a condom.’

I said, ‘Not Rebecca. She wouldn’t think of it.’

‘Nah.’

Julia would have thought of it.

13th of May: I’ll be there.

14th of May, Selena again. Don’t worry, I know you’re not going to answer this. I just like talking to you anyway. If you want me to stop, tell me and I will. Otherwise I’ll keep texting you. We had a substitute today for Maths, when she smiled she looked exactly like Chucky - Cliona got mixed up and called her Mrs Chucky and we all almost died laughing :-D

Rewinding, back to the small stories for laughs, trying to bring Chris back with her to a safe place. I said, ‘For a while, Mystery Girl’s able to convince Chris to stay away from Selena. Wouldn’t be hard: he’s pissed off with her anyway, and if Mystery Girl’s giving him something Selena wasn’t . . . But Selena keeps texting him. If he cared about her, if that was the real thing, then those texts had to get to him. After a while, it doesn’t matter what Mystery Girl’s bringing. Chris wants Selena back.’

Conway said, ‘And Mystery Girl has to come up with a new plan.’

16th of May, 9.12 a.m.. The morning before Chris died.