In Helsingborg on the Swedish west coast, a car is recovered from the harbor basin. Initially, the case seems clear: an accident. However, during the autopsy, it is revealed that the driver had been dead for a long time before the car plunged into the water. Commissioner Fabian Risk and his colleagues investigate the mysterious death. Someone believes they saw the deceased just last week. How is that possible? Risk has a suspicion, but it is so absurd that he initially cannot bring himself to believe it. One thing is certain, though: there will be more victims; a serial killer is at work. By sheer coincidence, the police have now picked up his trail. The body in the harbor basin was not the first victim, and certainly not the last...