“Difficult to tell how far the injuries predate death,” Thomas commented.

“Professor Thomas,” Quant explained, again for Rebus’s benefit, “has found evidence of bruising. Nothing that would have caused a fatality, unless there were underlying health issues.” She paused. “I missed them first time round.”

“Easily confused with lividity,” Thomas reassured her.

“Death occurred two to three years ago.” Quant’s eyes were on Rebus. “A DNA fingerprint should be straightforward enough, but someone needs to check the missing persons files—for the whole of the UK.”

“No biggie, then,” Rebus muttered, knowing she couldn’t hear him. She could see him, though, and smiled, sensing what he was thinking. He tapped a finger against the top of one arm.

“Distinguishing features?” she asked her colleague.

“No tattoos. No scars. No signs he was ever operated on. Dental records might be another route to establishing identity. I’d say the work was basic British NHS. Calluses on hands suggest manual labor of some kind. Or maybe he just enjoyed DIY. Ingrowing toenail on left foot, but hard to say if he’d had it treated or not. Nothing very exciting in the stomach or lungs. He was probably a moderate smoker. Might have killed him eventually.”

Rebus did a mime of a knife slashing a throat.

“Suspicious death?” Quant asked.

“The fact is, he hadn’t been in the water more than a day or two, and died several years before. So whether the death is suspicious or not, there are questions that need answering.”

Quant turned her attention to Rebus again. “Body was wrapped in something woolen—maybe a tartan travel rug; we have blue and red fibers. It covered the torso and the legs to just above the knees. This would have had to happen soon after death for the skin to adhere to the fibers. Once atrophy sets in, the epidermis is less obliging.”

Rebus nodded slowly, then mimed taking a drink. Quant’s forehead creased.

“Was he a drinker?”

Her colleague looked up, but Rebus was shaking his head and pointing at her.

“Oh,” she said. “No, sorry, I’m busy later.”

“Too busy to attend the Glasgow dinner,” Professor Thomas added, sounding put out.

Rebus shrugged and mouthed the words “Just an idea.” She nodded and got back to work.

It was dark by the time Siobhan Clarke and Malcolm Fox reached the canal. It had been Fox’s idea—try to work through the sequence of events. So they had parked on the industrial estate and started off from the alley where Billy Saunders had been sleeping.

“Though we don’t know for sure this is where he was,” Clarke argued, buttoning her coat against gusts that seemed to have originated in the Arctic.

“We don’t,” Fox agreed. “But he wanted a meeting nearby, somewhere he felt he knew the terrain. Once he was on the towpath, he would have plenty of notice of anyone coming from either direction.”