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.

The freight train arrives in Berlin. Tempers explode in Charlotte's household. Aspiring inspector Jänicke makes use of a surprising skill.

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.

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.

Jänicke spots a match that leads to two suspects in the Red Fortress massacre. Blackmail and bribes fuel a Soviet-German tug-of-war over the train.

Benda's widow gives Wendt a piece of evidence. A crisis bonds Helga and Nyssen. Fingerprints are found on the knife, but Charlotte notices an oddity.