The Oslo police are baffled. Crime scenes are being found covered with blood, but there is no victim. Only an odd series of numbers is left behind. When a girl is brutally raped in her apartment, Detective Hanne Wilhelmsen is charged with solving the case. Hanne quickly notices strange similarities with the blood-stained crime scenes. But the victim's father has started an independent hunt for the rapist...and Hanne will have to race against time to prevent a victim becoming a vigilante.