The rules on contamination didn’t seem to extend to senior officers and their flunkeys: Grogan stood in the living room, hands in pockets, examining the scene. The body of a young man lay on the black leather sofa. His fair hair was matted over a deep cut. More blood had dried on his face and neck. There were signs of a struggle: the glass and chrome coffee table overturned, magazines crumpled underfoot. A black leather jacket had been thrown over the man’s chest, a gentle act after the bloodshed. Stepping closer, Rebus saw marks on the neck, visible below the blood-lines. On the floor in front of the body sat a large green holdall, the sort you took to the gym or for a weekend trip. Rebus peered inside, saw a backpack, a single shoe, Angie Riddell’s necklace … and a length of plastic-covered clothes-line.

‘I think we can rule out suicide,’ Grogan muttered.

‘Knocked unconscious, then strangled,’ Rebus guessed.

‘You reckon it’s him?’

‘That bag isn’t just sitting there for fun. Whoever did this, they knew who he was, and wanted us to know, too.’

‘An accomplice?’ Grogan asked. ‘A mate, someone he blabbed to?’

Rebus shrugged again. He was intent on the corpse’s face, felt cheated by it: the closed eyes, the repose. I’ve come all this way, thanks to you, you bastard ... He stepped closer, lifted the jacket a couple of inches and peered beneath. A black slip-on shoe had been stuffed into Martin Davidson’s left armpit.

‘Oh, Christ,’ Rebus said, turning to Grogan and Jack. ‘Bible John did this.’ He saw disbelief mingled with horror in their faces. Rebus lifted the jacket a little higher so they could see the shoe. ‘He’s been here all the time,’ he said. ‘He never went away …’

The Scene of Crime team did their business, photographing and videoing, bagging and taping potential evidence. The pathologist examined the body, then said it could be removed and taken to the mortuary. There were reporters outside, kept at a distance by police cordons. Once the SOC team had finished upstairs, Grogan took Rebus and Jack up for a look. He didn’t seem to mind them being there, probably wouldn’t have minded if he’d had Jack the Ripper himself for an audience: Grogan was the man who’d be on TV tonight, the man who tracked down Johnny Bible. Only he hadn’t, of course – someone had beaten them to it.

‘Tell me again,’ Grogan said, as they climbed the stairs.

‘Bible John took souvenirs – shoes, clothes, handbags. But he also placed a sanitary towel in the left armpit. Downstairs … that was him letting us know who did this.’

Grogan shook his head. He would take some convincing. Meantime, he had things to show them. The main bedroom was just that, but beneath the bed were boxes of magazines and videos – hard core S&M, similar to the stuff in Tony El’s bedroom, text in English and several other languages. Rebus wondered if one of the American gangs had brought it to Aberdeen.