Franziska was taken hostage: This news hits Ballauf and Schenk in the heart. Not only do you have to solve the murder of a prisoner in the Cologne prison, you also urgently need to help your colleague. In addition to her job with the homicide squad, Franziska is also a volunteer probation officer. And the inmate assigned to her, Daniel Kehl, of all people, is now threatening her with a knife in the prison visitor's room. After ten years in prison, he is actually about to be released. But he is urgently suspected of having just murdered his cell neighbor Sergej Rowitsch. Kehl protests his innocence. But his fellow inmate Niklas Berg testified that he had been caught in the act. Is there a conspiracy against Kehl?