A young nurse is found cruelly murdered. Commissioner Vincent Ruiz asks the renowned Hamburg psychiatrist Dr. Johannes "Joe" Jessen for help. Jessen recognizes parallels in forensic medicine: the injuries suffered by the death victim agree in a terrifying way with the violent fantasies of his patient Robert Mohren. Is this the brutal killer? Does Jessen have to break his confidentiality to prevent further acts of violence? When a second murder occurs, it is already too late. Jessen comes under suspicion himself and has no idea that he is already part of a perfidious plan - which not only endangers his own life, but also that of his family.