A committee of congressmen from the United States travels to postwar Berlin to investigate the morale of American troops. Among them, the most methodical, a strict congresswoman from Iowa who, worried about the events that are taking place, decides to investigate who is protecting a cabaret singer accused of fraternizing with the Nazis during the war. She enlists Captain John Pringle, another Iowan, to assist in her investigation, unaware that he is Erika's current lover.