For ten years, the bodies of young women have been found every year around Christmas in Edinburgh. They were all naked, cleanly washed. Everyone's throats have been cut. The latest victim was Kirsty Summers, the fiancee of Detective Constable Tony McLean. But the Christmas killer made a mistake, and a grief-stricken McLean tracked him down and caught him. Twelve years later, a maniac is killed by a cellmate, and in the same winter, the murders begin again. Did the police make a mistake and arrest an innocent man? Or did the Christmas Killer have a copycat? Or maybe there is some other, more sinister explanation?