Gunn sat at his desk squinting at the computer screen. Subliminally he registered the sound of a foghorn not far out in the Minch, and knew that the ferry would be docking shortly.

He shared his first-floor office with two other detectives, and had a fine view from his window of the Blythswood Care charity shop on the other side of Church Street. Christian care for body and soul. If he cared to crane his neck he could see as far up the road as the Bangla Spice Indian restaurant with its luridly coloured sauces and irresistible garlic fried rice. But right now the subject matter on his screen had banished all thoughts of food.

Bog bodies, also known as bog people, were preserved human bodies found in sphagnum bogs in northern Europe, Great Britain and Ireland, he read on the Wikipedia page on the subject. Acidic water, low temperatures and lack of oxygen combined to preserve the skin and organs, so much so that it was even possible in some cases to recover fingerprints.

He wondered about the body laid out in the cold cabinet in the autopsy room at the hospital. Now that it was out of the bog, how quickly might it start to deteriorate? He scrolled down the page and looked at the photograph of a head taken from a body recovered sixty years ago from a peat bog in Denmark. A chocolate-brown face remarkably well defined, one cheek squashed up against the nose where it had lain in repose, an orange stubble still clearly visible on the upper lip and jaw.

“Ah, yes, Tollund Man.”

Gunn looked up to see a tall, willowy, lean-faced figure with a halo of dark, thinning hair leaning down to get a closer look at his screen.

“Carbon dating of his hair placed him from around 400 BC. The idiots who performed the autopsy cut off his head and threw the rest of him away. Except for his feet and one finger, which are still preserved in formalin.” He grinned and held out a hand. “Professor Colin Mulgrew.”

Gunn was surprised by the strength of his handshake. He seemed so slight.

Almost as if he had read his mind, or detected his wince as they shook, Professor Mulgrew smiled and said, “Pathologists need good hands, Detective Sergeant. For cutting through bone and prising apart skeletal structures. You’d be surprised how much strength is required.” There was just the hint of cultured Irish in his accent. He turned back to Tollund Man. “Amazing, isn’t it? After two thousand four hundred years, it was still possible to tell that he’d been hanged, and that his last meal had been a porridge of grain and seeds.”

“Were you involved in that post-mortem, too?”