‘Drug Squad took all the CCTV files off of Scotrail on Thursday,’ he said. ‘Can’t see them handing them over to Locust in a hurry, but when they do, you can bet there will be a few gaps. Cairns – and whoever he’s working with – has had several days to edit them.’

Abercorn directed Whitaker’s attention back to the photos.

‘Come on, think. You were there the whole time.’

‘Aye, hiding, remember? The motor was parked facing away from me, so I never saw the driver’s face at all. The other guy, I’m telling you, I stuck my heid above that fence for a quarter of a second each time. I’d just tanned a hunner and fifty grand’s worth of watches. If they’d looked up and seen me, I was fucked. Older guy, that’s all I could say for sure.’

Abercorn looked away towards the partially covered windows. There was nothing to see: Catherine could tell he was just trying to contain his frustrations.

‘Well, we do have another avenue we can pursue,’ he said.

‘Which is what?’

Abercorn nodded to the door.

‘We’ll leave the pictures with you, Liam,’ he said. ‘Give you time and space, see if it helps not to have us breathing down your neck.’

They exited the room into the dim hallway, but Abercorn evidently wasn’t speaking further until they were out of the building altogether. These walls had very interested and very untrustworthy ears.

‘Bob Cairns has been a cop in this city for over thirty years,’ he said quietly, back out on the pavement. ‘He’s got friends in every division, trusted contacts at every level. We start asking questions and it’ll get back to him in no time. He’s got at least two accomplices in this who will also have their ears to the ground and whose identities remain a secret. I’d bet the farm on one of them being Fletcher.’

‘Me too.’

‘There’s also at least one other, and we don’t know how far or how high this might go.’

‘Please tell me there’s a “but” to this.’

‘Oh, there is. But you won’t like it.’

‘Hit me anyway. What’s your other avenue?’

‘I think we need to go back and play nice with Glen Fallan.’

‘He knows nothing about this,’ Catherine assured him. ‘Trust me, this is coming from someone who would like nothing more than for him to be implicated.’

‘But this isn’t what we’d be asking him about. I dug a little deeper into his father’s record. Iain Fallan was in CID over in Gallowhaugh. Wild times: a law unto himself, fair to say. Saw himself like a frontier sheriff.’

‘You going to tell me Bob Cairns was his deputy?’

‘Among others. Including Bill Raeside.’

Catherine felt her cheeks flush with dismay, the anger of having been played coming back for a second pass.