Typical for the 1950s, the film tampers with historic events: The head of German military defense, Admiral Canaris, is strongly opposed to the Nazi regime and eventually participates in a conspiracy against Hitler. Obergruppenführer and head of SD Heydrich turns out to be his most dangerous adversary who spares no effort to get the supervision of military defense in his own hands. But when Heydrich dies – he is shot by Czech resistance fighters –, there seem to be no more obstacles for Canaris. However, he repeatedly warns against a war against the Soviet Union to no avail. Thus, he participates in the assassination attempt of July 20. But Canaris had been unpopular for some time, and is observed by the authorities. Finally, he is removed from his job and executed.