After the murder of an inmate in the prison, Inspectors Leitmayr and Batic have to move their office to the prison with the help of Kalli Hammermann, who was recently promoted to senior inspector, in order to investigate between the fronts of two rival prison groups with the support of correctional officer Claussen. Their leaders are driven by power games, vigilantism and corrupt dealings, making it extremely difficult for the police to solve the murder. When the model prisoner Scholz, who was released at the same time and who finally wants to live with his musically gifted son Ferdinand again, comes into the sights of the investigators, events come to a head for Leitmayr and Batic. Is the boy in danger?

Workers find a female torso in a sewer beneath Munich Central Station. During their investigation, Batic, Leitmayr and Hammermann come across disturbing violent videos on the Internet. The cases seem to be connected and it quickly becomes clear that there could be another murder soon. In their desperate search for the perpetrator, the detectives encounter a frightening world of crimes displayed online - and end up in danger themselves.