The professor shook his head thoughtfully. “No, it looks like a surgical scar. At a guess I would say that this young man has had an operation performed at some time on a head injury.”

Gunn was stunned. “Well, that means this is a much more recent corpse than we thought, doesn’t it?”

Mulgrew’s smile conveyed both superiority and amusement. “Depends what you mean by recent, Detective Sergeant. Brain surgery is probably one of the oldest practised medical arts. There is ample archaeological evidence of it dating back to Neolithic times.” He paused, then added as an afterthought for Gunn’s benefit, “The Stone Age.”

He turned his attention now to the neck, and the broad, deep wound that incised it. He measured it at 18.4 centimetres.

“Is that what killed him?” Gunn asked.

Mulgrew sighed now. “I am guessing, Detective Sergeant, that you have not attended many post-mortems.”

Gunn blushed. “Not many, sir, no.” He did not want to confess that there had only been one before.

“It is bloody well impossible for me to determine cause of death until I have opened him up. And even then, I can’t guarantee it. His throat has been cut, yes. But he has multiple stab wounds in his chest, and another in the right scapular back. There are abrasions on his neck that would suggest the presence of a rope around it, and similar abrasions on his wrists and ankles.”

“Like his hands and feet had been tied?”

“Exactly. He may have been hanged, hence the abrasions on his neck, or else he may have been dragged along a beach using that same rope, which would explain the sand in the broken skin on his knees and feet. In any event, it is far too early to be submitting theories on the cause of death. There are multiple possibilities.”

A darker patch of skin on the right forearm was attracting his attention now. He wiped at it with his swab, then turned to lift a scrubbing sponge from the stainless-steel sink behind him, and began roughly rubbing away the top layer of skin. “Sweet fucking Jesus,” he said.

Gunn canted his head to try to get a better look at it. “What is it?”

Professor Mulgrew was silent for a long time before looking up to meet Gunn’s eye. “Why were you so keen to know how long the body might have been in the bog?”

“So I can clear it off my slate, Professor, and hand it over to the archaeologists.”

“I’m afraid you might not be able to do that, Detective Sergeant.”

“Why?”

“Because this body has been in the peat for no more than fifty-six years—at the very most.”

Gunn felt his face colour with indignation. “You told me not ten minutes ago that you were not a bloody carbon-dating machine.” He enjoyed putting the emphasis on the bloody. “How can you possibly know that?”