‘Don’t you bloody “precaution” me. I’m no’ having another armed sodding standoff!’

Logan climbed over the drystane dyke, sticking to the edge of the next field – more rapeseed – making for the steading. He dropped his voice to a whisper. ‘What do you want me to do: sit on my backside waiting for you to turn up with the gun brigade? That’ll make great headlines, won’t it: “Police waste time while female officer is tortured to death.”’

‘This is no’ a game, Laz – your nutjob’s killed three people. I’m no’—’

‘And Chalmers is not going to be number four.’

‘For God’s sake! You’re no’ sodding Rambo, you can’t just—’

‘So stop wasting time shouting at me and get your firearms team organized.’ He hung up on her and stuck the phone in his pocket. Managed a whole three steps before the thing started vibrating. Tough, she could leave a message. ‘Everyone: phones on silent. Airwaves too.’

The barbed-wire fence at the end of the field was rusted and baggy, easy enough to climb over. On the other side a thicket of weeds and grass stretched away to the crumbled end of the steading. It grabbed at Logan’s legs as he waded through to the building.

Sim picked her way through the fallen masonry and down the side, where the undergrowth gave way to a gravel yard, enclosed by the L-shaped steading on one side and a sea of nettles on the other. She stopped at a window and peered inside, keeping her voice down. ‘Guv? ’

He joined her at the window. A red-white-and-blue Mini sat on its own in a disused cattle court. Its driver’s side wing was crumpled in, the windscreen a spider’s web of cracked glass. The number plate matched: it was Chalmers’s. ‘Damn. . .’

At least now they knew they had the right place.

Rennie reached for the handle on the sliding wooden door.

Sim’s eyes bugged, then she shoved him out of the way, sending him tumbling onto the gravel. ‘Don’t!’

‘Ow!’ He stared up at her, holding on to the elbow of his left arm. ‘What the hell was that for? ’

‘Have you never raided a cannabis farm before? ’ She held out a hand and helped him up. ‘Sometimes they wire door handles and window latches to the mains – booby-trap the place against rival gangs and the police. First place we did, DI McPherson ended up flat on his back all the way down the bottom of the drive. Hair sticking out in all directions, smoke coming out the lace-holes of his shoes. Had black fingernails for months after that.’

Rennie rubbed at his elbow. ‘Jacket’s got a hole in it now and everything.’