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

Rath confesses to a priest -- and later to Wolter. Charlotte charms medical student Rudi into performing a secret autopsy, which uncovers a vital clue.

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 witnesses a horrifying scene. In police custody, the Black Reichswehr leaders are visited by a collaborator. Charlotte fights for survival.

Greatly outnumbered, Rath, Henning and Czerwinski use their wits to fight their foes. Svetlana is tracked down. Dr. Schmidt forces a truth to be seen.