‘We have to make some unpalatable choices and swallow down some very bitter pills. I know what gets said about us, about me. Letting Off Criminals Under Secret Trades. Guys like Cairns are everybody’s hero because they swat a few mosquitoes. It takes a lot more work for a lot fewer plaudits when you’re trying to drain the swamp.’

And there it finally was. But he wasn’t finished.

‘We’re after the big players. Gary Fleeting doesn’t even register, and Frankie Callahan is a speck of dust. Folk here think the world starts and ends in Glasgow. We’re developing a picture of a massive, highly complex distribution system, not just UK-wide, but cooperating with forces overseas from Moscow to Marrakech.’

He indicated the mountains of files and documents threatening to collapse and swamp him like those tablecloths swamped the flames consuming Callahan and Fleeting.

‘Look at this shit. What do people think we do all day? Dream up new ways to get in the way of “real” police work? We’re trying to map the reach of a supplier who is a major node in this network. I couldn’t afford to have Callahan’s operation derailed at that point for the sake of putting a nothing like Gary Fleeting away for a five-stretch. What would that achieve?’

‘I think James McDiarmid’s mother might have a forthright take on that question.’

‘That’s making the assumption that Fleeting killed him. I’m just not as convinced as you that this is all quite what it looks like.’

‘What it looks like to me is pretty simple,’ Catherine retorted. ‘Gary Fleeting killed James McDiarmid over a girl, or who knows, there was no love lost: maybe the girl was just an excuse. A few days later, Tommy Miller tips off Bob Cairns and he intercepts Frankie Callahan’s next heroin haul. Frankie and Gary suss the source of the leak and go all Reservoir Dogs on Tommy Miller, but while they’re at it, one or more of Paddy Steel’s people shoot them and set fire to the place in revenge for McDiarmid. What part doesn’t add up?’

Abercorn produced a clear plastic document wallet from a drawer beneath his desk and handed it to her, a white A4 sheet visible within.

‘It’s the early lab analysis on yesterday’s heroin seizure,’ he said. ‘The stuff’s pure shit.’

‘Pure shit, as in totally uncut?’

‘No, as in shit. Garbage. Worthless. It’s mostly talcum powder and gypsum. There was only enough heroin in it to attract the sniffer dog.’

Catherine skim-read the report, confirming what he was saying.

‘So this wasn’t Frankie Callahan’s shipment?’

‘There was a shipment due, according to our sources, and previous shipments have been transferred using the left-luggage store at Central, but clearly that’s not what Bob Cairns intercepted yesterday.’