Treverberg. 1967. Residents of the most prosperous and rapidly developing city in Europe are faced with an unprecedented atrocity: during the lesson, an entire class was shot for no reason. The young police captain Andreas Lee will have to answer the question: what made the student bring a machine gun with him, kill everyone with whom he studied and commit suicide? Starting a hopeless investigation without evidence and witnesses, the captain does not suspect that the shooting is only the first link in a huge chain of events that cannot be logically explained. What will become of a person if control is reduced? Who will replace the socially approved mask if the unconscious breaks out? Are the massacres random or is it part of an elaborate plan? And what begins where the powers and competencies of the police end?