‘I don’t doubt you are, but the reason it wouldn’t be fair to say is that I had countersurveillance running: two other cars specifically checking I wasn’t being followed to this address. You had no chance.’

Catherine didn’t know whether to feel relieved that it hadn’t been down to her own incompetence or all the more appalled to know that several other officers had been watching her go off the reservation.

‘Team One clocked that I had a tail, and that’s why I went up past Tollcross Park. It was so Team Two could race ahead and do a reciprocal to get a look at you, see who you were.’

‘Why did you carry on to your destination, then? Or did you take me to Stevie Fullerton’s house as a joke? And why are you running countersurveillance?’

‘It’s no joke, and though I’m running countersurveillance because I’ve come to Stevie Fullerton’s house, it’s not Stevie I’ve come to see. Why don’t you join me? I think you’ll find it instructive.’

He gestured to her to walk towards chez Fullerton, whose electronic gates were swinging open up ahead.

‘I have to say you’re taking this rather well,’ she said apologetically.

‘Running Locust, you get pretty thick-skinned. Besides, you’re not the only one to think there’s a bent-polis scenario in play here. You just went after the wrong cop.’

‘And which would be the right one?’

‘That’s what I’m hoping Liam Whitaker can help us ascertain.’

‘Whitaker’s here? With Stevie Fullerton?’

‘Hence the countersurveillance. He’s been in hiding since the robbery, as you know, but not just to avoid arrest. He’s in fear for his life, specifically from the police. Stevie Fullerton has been sheltering him for a couple of days. He got in touch through back channels; Stevie’s wise enough to know you can’t hide for ever, and mercenary enough to spot an opportunity. We’ve had access on the understanding that Whitaker’s whereabouts is not disclosed to the police at large: not until certain matters have been resolved, at which point he’ll be our witness.’

‘Had access? You’ve seen him already?’

‘Yesterday. Sunday. I’ll have to vouch for you, because you weren’t part of the deal, but understand this much: when this is over, Whitaker walks.’

‘Fine with me. But what does Fullerton get out of this “opportunity”?’

Abercorn tapped his wrist. Catherine thought he meant that they had to hurry along and there wasn’t time to discuss it. Then she worked it out.

‘The price of doing business,’ she remarked distastefully.

‘Letting Off Criminals Under Secret Trades,’ Abercorn replied.