The picture that the pathologist painted with his words was suddenly very vivid to Gunn. He wasn’t sure why, but somehow he pictured it at night, with a phosphorescent sea breaking over compacted silver sand glowing in the moonlight. And then the blood turning white foam crimson. But what shocked him almost more than anything else was the thought that this brutal slaying had taken place here, on the Isle of Lewis, where in more than a hundred years there had been only two previous murders.

He said, “Would it be possible to take fingerprints? We’re going to have to try to identify this man.”

Professor Mulgrew did not answer immediately. He was focused on reflecting the scalp away from the skull without tearing it. “It’s so bloody desiccated,” he said. “Brittle as hell.” He looked up. “The fingertips are a bit wrinkled from fluid loss, but I can inject a little formalin to rehydrate them and you should get perfectly acceptable prints. Might as well take a DNA sample, too.”

“The police surgeon already sent off samples for analysis.”

“Oh, did he?” Professor Mulgrew did not look pleased. “Unlikely to provide any enlightenment, of course, but you never know. Ah . . .” His attention was suddenly taken by the skull, revealed finally by the peeling back of the scalp. “Interesting.”

“What is?” Gunn reluctantly moved a little closer.

“Beneath our chap’s surgical scar here . . . a small metal plate sewn in to protect the brain.”

Gunn saw a rectangular, dull grey plate about two inches long, sewn into the skull with metal sutures looped through holes at either end of it. It was partially obscured by a layer of lighter grey scar tissue.

“An injury of some kind. And very probably a little mild brain damage.”

At Mulgrew’s request Gunn stepped out into the corridor and watched through the window that gave on to the autopsy room as the pathologist took an oscillating saw around the top of the skull to remove the brain. When he went back in, the professor was examining it in a stainless-steel bowl.

“Yes . . . as I thought. Here . . .” He poked at it with his finger. “Cystic encephalomalacia of the left frontal lobe.”

“Meaning?”

“Meaning, my friend, that this poor bugger didn’t have much bloody luck. He had some kind of head injury that damaged the left frontal lobe, and probably left him . . . how can I put it . . . one sandwich short of a picnic?”

He returned to the skull, and with a delicate scraping of his scalpel, pared away the film of tissue growing over the metal plate.

“If I’m not mistaken, this is tantalum.”

“What’s that?”