I let my spine go loose like a teenager’s, knees everywhere, and gave Rebecca another smile. Rueful, this one. ‘I need a hand again. I’m good at my job, I swear, but every now and then I need someone to help me out or I’ll get nowhere. I’ve got a feeling maybe you might be able to do that for me. Would you give it a shot, yeah?’

Rebecca said, ‘Is it about Chris?’

Not too shy to dig in her heels a bit. I made a face. ‘I’ve gotta tell you, I’m still trying to work out what it’s about. Why? Has something happened to do with Chris, yeah?’

She shook her head. ‘I just . . .’ Gesture at Conway, with the bundle of hands and skirt. Conway was picking her nails with the cap of her Biro, didn’t look up. ‘I mean, because she’s here. I thought . . .’

‘We’ll try and figure it out together. OK?’

I shot her the warm crinkly smile. Got a blank look back.

I said, ‘So let’s start with yesterday evening. First study period: where were you?’

After a moment Rebecca said, ‘The fourth-year common room. We have to be.’

‘And then?’

‘We get our break. Me and my friends, we went outside and sat on the grass for a while.’

Her voice was still a scraped-down wisp, but it got stronger on that. Me and my friends.

I said, ‘Which friends? Holly and Julia and Selena, yeah?’

‘Yeah. And some others. Most of us went out. It was warm.’

‘And then you had second study period. You were here in the art room?’

‘Yeah. With Holly and Julia and Selena.’

‘How do you go about getting permission to spend a study period here? Like who asked who, and when? Sorry, I’m a bit . . .’ I did shrug, head-duck, sheepish grin. ‘I’m new on this. Don’t know the ropes yet.’

More blank. Great with the young people, me, I’ll get them relaxed, I’ll get them talking . . . Lovely Big Bro was striking out.

Conway was squinting at a thumbnail against the light. Missing nothing.

Rebecca said, ‘We ask Miss Arnold – she’s the matron. Julia went and asked her day before yesterday, at teatime. We wanted to go for first study, but someone was already going then, so Miss Arnold said to go for second study instead. They don’t like too many people being in the school after hours.’

‘So at break yesterday evening, yous got the key to the connecting door off the other girls who’d been up here?’

‘No. We’re not allowed to pass it around. Whoever signs the key out has to sign it back in, when they said they would. So the other girls gave it back to Miss Arnold, and then we went and got it off her.’

‘Who did that?’