In 1929, a freight train traveling from the Soviet Union is hijacked. Meanwhile, Chief Inspector Gereon Rath from Cologne pursues a mission in Berlin.

While interrogating König, Rath loses control of the situation. Charlotte moonlights to make ends meet. An alter ego commits a betrayal.

Rath's pharmacist gets shady instructions. Rath learns who's behind the train smuggling operation and why, and recalls the last time he saw his brother.

Greta goes on a romantic outing with Fritz. Krajewski finally reveals where the film is hidden. A new patient is brought to Dr. Schmidt for treatment.

A mass grave is found in the woods. Charlotte's sister Toni makes a troubling discovery. A meeting with Homicide leads Rath to a dreadful realization.

Trochin transacts his deal with Benda. Moritz snoops in Wolter's cellar. Rath and photographer Gräf gather proof of a secret air force base in Lipetsk.