‘According to Fallon’s statement,’ Meehan says, spinning his chair round to face us, ‘he got off the bus just before half-seven, and he knocked on Aislinn’s door just before eight – that part’s confirmed by the witness who was walking his dog. So that’s half an hour for the whole walk – from the bus stop to the top of Viking Gardens, up to Tesco and buy flowers, back down to her house. When I went at a normal pace, it came out at twenty-seven minutes. When I went as fast as I could without actually running, I knocked six minutes off that.’

I say, ‘Meaning Rory could have had almost ten minutes to spare.’

‘More,’ Steve says. ‘Here’s the good part. Stanton pulled CCTV from the 39A route and had a look, first thing this morning. Rory got on the bus at ten to seven, not just before seven like he told us, and he got off it at quarter past, not just before half. He could’ve misremembered, or just been estimating the times, but . . .’

‘But he was obsessing about being late to Aislinn’s,’ I say, ‘in case she got her feelings hurt and dumped him and his life was ruined or whatever. Nah: he didn’t estimate, and he didn’t misremember. He’s got anything up to twenty-five minutes unaccounted for, and he was fudging because he doesn’t want us knowing that.’ That blood-smell flares at the back of my nose again. He’s so tempting, Rory, all fluffy and big-eyed and just begging for the killer bite; it would be so satisfying to hammer on his door, drag him back in and shove his face up against the CCTV screen. ‘Good. When we bring him back in, he’d better have a great explanation for what he was doing. Have we got footage from the area yet?’

‘Yeah,’ Kellegher says, leaning back from his monitor. Kellegher is long, freckly, laid-back, and useful enough that he’s going to end up on the squad sooner or later. ‘The bad news is, there’s no cameras between the 39A stop and Viking Gardens, or between Viking Gardens and the Tesco – so we can’t verify Fallon’s route, or the timing. But we’ve got him buying the flowers in Tesco. He paid at 7.51, which matches his story.’

‘No surprise there,’ I say. ‘He had to know Tesco would have him on camera; he wouldn’t lie about that. We need to widen the area of Stoneybatter where we’re pulling CCTV. Whatever Rory was doing in that missing time, it could have taken him off the route he gave us. Reilly, you can get on that.’ Meehan reaches for the book of jobs.

Reilly glances out the window – it’s getting ready to rain – and back at his monitor. ‘I’m not done watching what we’ve got.’