In the waning weeks of World War II, chaos reigns in the nearly defeated Nazi Germany. As people flee for cover from the omnipresent air raids, American prisoner of war Foster MacLain escapes his German captors and seeks refuge in the house of Professor Julius Angermann. The professor, fervently awaiting an end to the war, breaks the law by abetting Foster, the enemy. Soon after, the professor's daughter Erika arrives home and eagerly opens a letter from her soldier fiancé, Hugo Von Metzler. Erika is angry when she learns that her father is harboring a fugitive, but when German soldiers, looking for the American, knock at their door, she hides Foster in her bathroom. After the soldiers have gone, the professor gives Foster a coat to wear over his uniform and he leaves. When gunfire follows his departure, the Angermanns are certain that Foster has been killed. Soon after, a bomb strikes the house and kills the professor. Now alone, Erika ventures to Berlin in search of her cousin Karl. In Berlin's bombed-out streets, the Germans are fleeing the oncoming Russians, but Karl welcomes Erika to his house. He introduces her to his lodgers, the self-centered, opportunistic Berta and Fritz Graubach, who resent Erika's intrusion. Several days later, Russian troops arrive to occupy the city, and fearing for Erika's safety, Karl hides her in the attic. The Russians take over Karl's house, and one night, during a drunken revelry, a corporal finds Berta hiding in the kitchen and begins to molest her. To save herself, Berta tells of the attractive young girl in the attic, sending the corporal rushing up the stairs to break down the door. When Karl tries to defend his cousin, the Russians shoot him in the back. After the corporal tries to rape Erika, she climbs out onto the roof and he follows and falls to his death. Erika is charged with murder until the lustful Col. Dmitri intervenes on her behalf. Dmitri expects sexual favors in return, and even though Erika rejects his advances, he forces her to go out with him. At a nightclub, Dmitri drunkenly proposes to Erika and then passionately kisses her. After excusing herself to fix her lipstick, Erika meets Lori, the club's sympathetic piano player, who shows her a hidden stairway and directs her to a barge that will transport her across the river to American occupied territory. Meanwhile, Foster, who has survived the war and was promoted to major, has been sent to American occupied Berlin, and has kept the coat given to him by the professor who saved his life. Foster's adoring female assistant, Lt. Berdie Dubbin, offers to help him find his benefactor and discovers that the professor has been killed but Erika is still alive. One day, Erika is picking through the rubble of Berlin when the now prosperous Graubachs chance upon her and insist that she come home with them. When they introduce her to their "nieces," Erika fails to realize that the Graubachs are running a brothel until one night, one of the Graubachs' gentlemen callers assails her in her room. Erika runs out onto the street, where Graubach reproaches her for offending his patron. Just then, two American MPs drive by and come to her rescue. When Graubach hurls a racial epithet at Corp. S. Hanks, a black soldier, Erika earnestly apologizes for his behavior. Soon after, Erika meets Lori, who is now playing piano at a local club. Lori takes pity on Erika and gets her a job in a dunk game which requires her to sit on a diving board while GIs throw balls a target that will dump her into a pool below. One night, Foster comes to the club and sees Erika. When he offers to help her, Erika is wary, but asks him to find Hugo. Soon after, a man from the health department comes to Erika's apartment and is greeted by Lori, her roommate. The man tells a shocked Lori that Erika has been registered as a prostitute by the Graubachs and therefore must report monthly for examinations. Right after the man leaves, Foster arrives and asks Erika to go for a drive. In a bombed-out area of the city, Foster points Erika to the sorry hut where Hugo is now living with another woman. Hugo, who has lost an arm in war, has become bitter and indifferent, and when he asks Erika to return her cherished engagement ring so that he can buy an artificial arm, she is devastated. Erika silently hands him the ring and leaves. On the drive home, Foster, sensing her disappointment, asks Erika to join him on a barge trip along the Rhine. As they travel the countryside, Foster forces Erika to confront the losses and sadness in her life and she finally breaks into tears. Foster then confides that he has fallen in love with her and they kiss. Back in Berlin, Erika tells Lori that she plans to apply for a passport so that she can accompany Foster back to America. When Lori informs Erika that she is registered as a prostitute and therefore is unable to leave the country, Erika rushes to the security administration office in disbelief. Lori tries to notify Foster about Erika's distress, but Lt. Dubbin intercepts the call and snidely advises Foster that he offer Erika nylons and not marriage. At the security office, Erika is waited on by Hanks, the black soldier who saved her from Graubach. Remembering her kindness, Hanks obliterates the designation "prostitute" from the record and then hands over her papers. Her name cleared, Erika runs to meet Foster and begin a new life.