Two murders, twenty years apart. Time for revenge . . .

When the body of a red-haired young man is washed up on the shore of the beautiful Isle of Mull, Detective Superintendent Lorimer's tranquil holiday away from the gritty streets of Glasgow is rudely interrupted. The body has been bound with twine in a ghoulishly unnatural position that strongly reminds Lorimer of another murder: a twenty-year-old Glasgow case that he failed to solve as a fledgling detective constable and which has haunted him ever since.

As a local cop takes charge of the island murder investigation, Lorimer tries to avoid stepping on her toes. But as the similarities between the young man's death and the cold case grow more obvious, Lorimer realizes that there could be a serial killer on the loose after all these years. As the action switches dramatically between the Mull murder and the Glasgow cold case twenty years earlier, Lorimer tries desperately to catch a cold-hearted killer. Has someone gotten away with murder for decades?