‘Probably. If you think it’s important.’ He seemed surprised and a little sceptical. Had the detectives come all this way just to look at some snaps? ‘I had the camera to record specimens on the island, but I know I took photos of some of the characters in the street too.’ He got to his feet and rifled through the drawers of an elderly dresser. Joe was about to tell him not to bother, that it wasn’t important, when the professor pulled out an album almost falling apart at the seams. He put it on the table and Joe stood up to get a better look. Charlie stayed where he was.

And there, suddenly, was Harbour Street, familiar but subtly changed, the images slightly faded. A young Malcolm Kerr standing by the harbour wall with an older man and in the background the fisheries building, sparkling and new in bright sunlight. The older man grinning and the younger glaring. On the opposite page a woman was pushing a big, old-fashioned pram down the road past the church. She had a cigarette in one hand and controlled the pram with the other.

‘Why did I take that?’ Craggs frowned. ‘After all this time, I really can’t remember.’

He turned the page of the album and there was a group of people posing outside the Coble. Summer. The women in sleeveless dresses and sandals, the men squinting into the sunshine. In the middle Billy Kerr, with a big drunken grin, next to a large woman in a shapeless floral dress.

‘I remember that day,’ Craggs said. ‘Billy’s fiftieth birthday.’ He pointed to the fat woman. ‘That’s Val Butt. She was the landlady. And that’s her son, Ricky. Local wheeler and dealer. Always seemed to have cash, and none of us knew where it had come from. Flashy. He moved on very quickly. I’d guess that Mardle was too tame for him.’

Joe looked at the image of Ricky Butt, a dark-haired young man, dressed in denim, but his attention was immediately drawn to the woman who stood in front of him. Margaret Krukowski. No longer the young woman of the wedding photograph, here aged in her thirties, but still lovely. On her face a smile that was tense and unnatural, as if she hated having her picture taken.

Craggs turned the page again and this time it was a long shot up Harbour Street, with the big house at the end. Even from that distance it looked as if it was falling into disrepair. And on the same page, Kerr’s boatyard. In place of the corrugated-iron shed there was a Portakabin, rather smart, a sign on the door saying Kerr’s Charters. Joe supposed this was the office where Margaret had answered the phone and booked in customers, before she became too expensive.

‘Was Margaret working there when you first knew her?’ he asked.