1950, the extensive network of sewers beneath the city of Berlin. This cesspool underworld, whose sewers led from the eastern to the western part of the city and vice versa, had become the main transshipment point for a gang of criminals for their hot goods. It's a dirty business, but anyone who dared to disrupt or stop it could expect to disappear into the sewer system forever. But detective Steffens and his colleague Rödel are on the trail of the cold-blooded criminals and do everything they can to put a stop to them and put them behind bars.