Klaus, a former Nazi doctor, practiced horrific, sadomasochism experiments on children during World War II. After the war, he goes into exile in a remote village in Catalonia, where he continues to rape and torture young boys. He kills his latest victim with a blow to the head, taking photographs of the crime. Angelo, one of Klaus' victims, spies on him from a window, and steals incriminating writings and photographs of the doctor's crimes. Klaus tries to commit suicide by jumping from a tower. He survives, but he is left paralyzed and unable to breathe on his own, confined permanently in an iron lung to survive.