“I’m not saying he admitted you were. But something about our questions upset him. Where were you that night?”

“What night?”

“Sunday before last.”

“At home studying.”

“You didn’t see Jason?”

“We’re not inseparable, you know. Yes, he’s my mate, yes, I give him a lift to school, but we’re not joined at the hip.”

“Would your parents vouch that you were at home that evening around half past ten?”

“I suppose so. If they remember. I was up in my room most of the evening revising, and they were downstairs watching TV, so I didn’t see them.”

“It wouldn’t have been too hard to nip out without being seen, then, would it?”

“Why would I want to do that?”

“For a smoke.”

“I don’t smoke.”

“You know what I mean. And you do have a track record with drugs.”

“Oh, that fucking stupid party again,” said Chris. “I wish I’d never been there. Do you know, I had no drugs at all that night? I didn’t even get high. Nothing. OK, so I had a few cans of beer, and I wasn’t old enough to drink. Big fucking deal. Arrest me. I was only there cause there was a girl I fancied. A college girl. It’s not as if we’re constantly surrounded by totty at school.”

“I think the statute of limitations has run out on your underage drinking,” Banks said. “Not to mention lust.”

Even the duty solicitor, Willy Carnwood, managed a smile at that.

“Who had the knife, Chris? Was it you or Jason? He denies it, but then—”

There came a knock on the door, followed by DC Gerry Masterson carrying a file folder. Normally, Banks would have been annoyed at the interruption, but he had asked Gerry to come immediately if anything turned up at the lab. By the expression on her face, something had.

Banks thanked her, noted what had happened for the tape recordings and took the folder. Annie edged closer to read it over his shoulder. Gerry remained in the interview room, standing by the door.

“Hmm,” said Banks. “This is interesting.”

“May I see it?” asked Willy Carnwood.

Banks had hoped he wouldn’t ask, but as he had, he knew he would have to pass the file across. But not just yet. “It’s just come in, as you know,” he said. “I’ll need to refer to it during my questioning. Then I’ll make sure you get to see it.”

Carnwood nodded. “OK.”

“Want to know what it says?” Banks asked Chris.

Chris looked nonchalant, bored even. “I suppose you’re going to tell me anyway,” he said with a sneer.

“Yes. I think we might be able to bring these proceedings to a swift conclusion.”

“You mean I can go home?”