Berlin, 1929. Detective Inspector Rath, was a successful career officer in the Cologne Homicide Division before a shooting incident in which he inadvertently killed a man. He has been transferred to the Vice Squad in Berlin, a job he detests, even though he finds a new friend in his boss, Chief Inspector Wolter. There is seething unrest in the city and the Commissioner of Police has ordered the Vice Squad to ruthlessly enforce the ban on May Day demonstrations....

Berlin, 1931. A power struggle is taking place in Berlin's underworld. The American gangster Abraham Goldstein is in residence at the Hotel Excelsior. As a favour to the FBI, the police put him under surveillance with Detective Gereon Rath on the job. As Rath grows bored and takes on a private case for his seedy pal Johann Marlow, he soon finds himself in the middle of a Berlin street war. Meanwhile Rath's on-off girlfriend, Charly, lets a young woman...