Police of Barcelona finds the body of a man brutally murdered. From that moment the criminal investigation begins looking for evidence to determine who was the murderer. However, the resolution of the case will be affected by the rivalry between the chief of homicides and that of the scientific police for the same woman. When they discover a second body they realize that they have to give up their personal confrontation to solve the case. The tests involve them in a live game conceived by a young psychopath and his submissive friend.