He said something else after that, probably equally revolting, but I wasn’t really listening to him. I was listening to the new arrival yelling and watching him smear drool on the glass and thinking that if, just for the sake of argument, it had been some kind of . . . performance, it was as good as I’d ever seen. I was putting it all together and – then, at least – it made perfect sense.

I began walking away just as George and Marcus steamed into the 136 like a two-man Tactical Support Unit, so I didn’t see what happened after that. Must have gone OK though, because apparently the kid settled down and was discharged the following morning. I’ve no idea what happened to him after that. He might be getting therapy somewhere or he might be playing chicken with himself on a motorway somewhere else, but either way, he was the one that put the idea into my head.

Right then, though, while they were pumping a syringe full of benzos into his backside, I needed to get to my room as quickly as possible and make a call while it was still fresh in my mind.

‘So, any news?’

‘Bloody hell, Al, give me a chance.’ Banksy’s voice was low, like he didn’t want to be overheard. ‘I only saw you yesterday.’

‘Quick and the dead, mate.’

‘Far as I know they’re still waiting for forensics.’

‘Yeah, I mean there’s no rush. It’s only one less nutter, after all.’

‘To be fair, I think there’s a bit of a backlog, all right? Besides which I don’t think they’re hopeful it’s going to be a lot of help.’

I knew what he meant. Like forensicating a hotel room. More prints and DNA than you can shake a swab at. In the case of Kevin’s room that would certainly include all the staff and most of the patients.

I started to tell him the real reason for the call, told him what I’d just seen.

‘The Informals come in and go out,’ I said.

‘Right.’

‘Same with anyone who gets brought in on a 136.’

‘So . . . ?’ Banksy did not sound convinced.

‘So, let’s say Kevin had got himself involved with some nasty drug dealers.’

‘They’re all nasty,’ Banksy said.

‘Properly nasty, yeah? Say Kevin’s in over his head. Say he’s been paid up front for something he doesn’t deliver, or maybe he decides he wants to get out of it but he knows too much. It’s the perfect way to get rid of him.’

There was silence for a bit. I could hear squad-room noises in the background, phones and chit-chat. I felt like someone who’d lost a child and then seen a woman out with her new baby. OK, that’s putting it a bit strong, maybe, but you know what I’m saying.

‘Go on then,’ Banksy said.