“Well. The motive doesn’t even have to be anything big; I mean, as far as we know, it’s not like he was planning on killing her. It looks more like it just happened. When he realizes she’s dead, he drags her body to the basement—unless they’re down there already—and puts her under the concrete. He was strong for his age; he’d worked part-time on a building site, that summer, fetching and carrying. He would’ve been able for it.” Another quick glance. I picked ham out of a back tooth and watched him blandly.

“At some stage in all this, Kevin finds the note Rose was going to leave for her family, and he realizes he can use it to his advantage. He stashes the first page and leaves the second where it is. The idea is, if Francis leaves anyway, everyone will basically tumble to the original plan: the two of them have gone off together, and the note’s for her parents. If Francis ends up going home when Rose doesn’t show up, or if he gets in touch with his family at some stage, everyone will think the note was for him and she’s gone off on her own.”

“And for twenty-two years,” I said, “that’s exactly what happens.”

“Yeah. Then Rose’s body turns up, we start investigating, and Kevin panics. According to everyone we’ve talked to, he was pretty stressed out the last couple of days, and getting worse. Finally he can’t take the tension any more. He digs out the first page of the note from wherever he’s been keeping it all this time, he spends one last evening with his family, and then he goes back to the place where he killed Rose and . . . Well.”

“He says his prayers and takes a header out the top-floor window. And justice is served.”

“More or less, I guess. Yeah.” Stephen watched me covertly, over his coffee, to see if he had pissed me off.

I said, “Well done, Detective. Clear, concise and objective.” Stephen let out a quick breath of relief, like he was coming out of an oral exam, and dove into his sandwich. “How long do you think we’ve got before that turns into the official Gospel according to Kennedy, and both cases get closed?”

He shook his head. “A few days, maybe? He hasn’t sent the file upstairs yet; we’re still gathering evidence. He’s thorough, Detective Kennedy is. I mean, I know he has his theory, but it’s not like he’s just slapping it onto the case and throwing the whole thing away. He’s talking like we—me and the other floaters—we’ll be staying with Murder for the rest of the week, anyway.”