‘Shit,’ I say, straightening up fast. ‘Were you in the observation room when Breslin asked him for evidence that Aislinn had a stalker?’

‘Jesus.’ Steve catches his breath with a hiss. ‘Yeah, I saw that. Rory started to say something about having seen some bloke on Saturday night, and Breslin shut him right down.’

‘Breslin and me,’ I say. ‘I was right in there, backing him up, like a bloody idiot. But listen: the guy Rory saw, that can’t have been Breslin. If it was, Rory would’ve recognised him on Sunday – or at least today, when he brought it up. And you and me would’ve seen that, if he recognised Breslin; we couldn’t have missed that. Breslin’s not the one who was in Stoneybatter Saturday night.’

‘Huh,’ Steve says. He’s gone immobile again, only his mind moving, twisting and rearranging the case like a Rubik’s cube. ‘Try this. Breslin was Aislinn’s fella. Over the last few weeks, he starts to suspect she’s two-timing him. Maybe he checks her phone – it only had a swipe lock, remember? – and he finds the texts between her and Rory. And then, sometime last week, he finds Rory’s text about the dinner date.’

‘Breslin wouldn’t like being two-timed,’ I say. ‘The ego on him; he wouldn’t like it one little bit.’

‘But he’d have better sense than to do his own dirty work.’ Steve’s eyes come up to meet mine. ‘You know who he would’ve brought in.’

I say, ‘McCann.’ The thought of putting yourself in your partner’s hands like that does something weird inside my head. I look at Steve and he looks different from ever before: his freckles are more vivid, the lines of his mouth are more definite, I can almost see warmth coming off his skin. He looks more real.

‘Yeah,’ he says. ‘McCann.’

I say, ‘Breslin sets up a beautiful alibi, just in case – what do you bet him and the missus had friends over, Saturday night, or went to a nice crowded restaurant? And McCann heads down to Stoneybatter to sort out that cheating bitch.’

‘The way it went down,’ Steve says. ‘That can’t have been the plan.’

There’s a question in his voice. He means did they want Aislinn dead.

‘Nah,’ I say. ‘Just for two-timing Breslin? He might’ve been raging, but I don’t care how close him and McCann are: there’s no chance McCann would get himself into something like this just because Breslin can’t keep his mot in line.’

‘So McCann was just planning to talk to her. Drop a few hints about why it’s a bad idea to cheat on a cop. Maybe talk to Rory, too, warn him off. Just talk.’

He badly wants to believe that. A surprisingly big part of me does, too. ‘Maybe,’ I say. ‘Probably. Only something goes wrong. Maybe Aislinn goes to scream and McCann panics, something like that.’