‘Here’s what we’ll do,’ I say, closing my notebook. ‘You go home. Get some sleep. We’ll talk to Aislinn’s neighbours and see if any of them happened to look out their back windows and see you in the laneway between, say, 8.30 and 8.40. If they did, you’re off the hook: you wouldn’t have had time for the other thing.’ Obviously we’ve already talked to the neighbours, and I’m betting they would have mentioned some weirdo hanging around the laneway, but this doesn’t seem to occur to Rory. ‘Come back in to us tomorrow to sign your statement, and we’ll do updates then. Fair enough?’

Rory pulls his coat around his shoulders, not even trying the sleeves. ‘Yes. OK.’

‘We’ll come pick you up,’ Breslin says, keeping it just the right side of a threat. He stands up and stretches. ‘You’re not planning to be anywhere other than your flat or the bookshop, are you?’

‘No. I’m going nowhere.’

‘Good plan,’ Breslin tells him. He pulls the door open and sweeps his hand at it with a little mock bow. ‘After you.’

Steve is in the doorway of the observation room, suit jacket over his arm, sleeves rolled up against the heat. His eyes meet mine for a long level second. Then we’re past him and down the corridor, Rory speeding up towards the draught of cold fresh air coming up the stairwell, Breslin humming happily to himself under his breath.

Me and Breslin watch from the doorway as Rory heads off across the cobblestones. He looks small and messy, slams of wind flapping his coat and tangling in his hair, swerving him off course. It’s practically dark. Just a couple of months of bodyguard work, and I’ll have enough saved up for a holiday somewhere blazing hot in eye-shattering colours and very far away.

‘Enlighten me,’ Breslin says pleasantly. ‘Why is this guy going home?’

I say, ‘We’re nearly there with him. He was right on the edge, till that pause gave him a chance to pull his head together – and if we could get him there once, we can get him there again. But if we put him under arrest, he’s gonna get a solicitor in there, and we can say goodbye to any chance of a confession.’

‘We don’t need a confession, Conway. We’ve got enough circumstantial stuff to bury him alive.’

Which is probably true. I don’t care. My last murder case: this one isn’t gonna be tacked down with circumstantial this and reasonable inference that. I’m gonna hammer a stake right through its heart and leave it dead as dirt.

‘I want one,’ I say. ‘We can afford to leave Rory till tomorrow.’

‘Unless he jumps in the Liffey.’

‘He won’t. He still thinks I might wind up believing him. He wants that.’

Breslin watches me. ‘Is he right?’