In occupied Gdynia, Lieutenant Franz Neumann is drawn into another dangerous espionage game. Engineer Redliński, pursued by the Gestapo, unexpectedly finds Franz, seeking salvation from him. Meanwhile, Bergman recruits the brutal criminal Wulf to track down a traitor in the Kriegsmarine. Franz approaches Bergman's mysterious adjutant, Jorg, to gain information about Bismarck's operational plans.

Franz, investigating the murder of a janitor, discovers that the killer fired a Russian rifle, suggesting the involvement of a Soviet spy. His investigation leads him to Redliński, who reveals that his daughter Hedwig may know the location of the scientific documentation.