Which sounds a lot like a sideways explanation for why it couldn’t have been me, honest, Detective. You get them a lot. Mostly you get them from killers. I nod along, concentrating hard on all these valuable insights.

Rory says, ‘But a lot of people aren’t like that. It took me a while to realise, when I was younger: some people spend all their time focused on what’s actually happening.’

‘I know what you mean,’ I say. Confidentially: ‘You get a lot of cops like that. No imagination.’

That gets an automatic half-smile, but Rory’s too deep in his story to pay much attention to me. ‘So if a man like that were to run into Aislinn, he wouldn’t know how to prepare for the fact that his bubble was, almost definitely, going to burst. And when it did . . .’

‘I get you,’ I say, doing a little focused frown. ‘At least, I think I do. Tell me what you’re picturing. Specifics.’

Rory draws patterns on the table with one fingertip. He says, slowly, ‘I think he was someone who wouldn’t even have come onto your radar, because he knew Aislinn so briefly. They meet in a nightclub, maybe, or through her work, and they get talking. Maybe he gets her phone number and they meet up for a drink, or maybe it never even gets that far. But his mind’s already gone wild spinning stories, and he’s intoxicated by the feeling – especially since, to him, it’s brand-new.’

By now Breslin is waiting in the observation room, rolling his eyes and muttering at me to get a move on, while our coffee goes cold. He can do some deep breathing. If Rory needs all day to talk himself into this, then he’s gonna get all day.

‘And then, for whatever reason, Aislinn decides not to go any further with the relationship.’ Rory looks up at me. His fingers are pressing down hard on the tabletop. ‘If you’re not used to that reality check, it’s devastating. It’s like I imagine cold turkey would feel to a heroin addict: actual physical upheaval, as well as psychological. Your body and your mind, floundering.’

‘So he goes after her?’ I say.

Rory shakes his head vehemently. ‘No. Not like that. Someone who would do that, attack a woman just for breaking up with him after an evening or two – that’s a monster. A psychopath. And Aislinn wouldn’t have got involved with a monster to begin with. Just because she enjoyed daydreaming, that doesn’t mean she was oblivious to reality. This man must have been a decent guy. Things just got out of control.’