Two US Air Force officers find German girlfriends during the Russian blockade of occupied Berlin with unexpected results.
Russians blockade Berlin so that the western allies will leave; but instead they begin flying in supplies to the western sectors. Sergeant Hank Kowalski (Paul Douglas) and Sergeant Danny MacCullough (Montgomery Clift) are flown from Honolulu to Berlin. Danny works on a plane in the air lift which is honored for the 100,000 flights. In a ceremony Germans thank them, and Federica Burkhardt (Cornell Borchers) kisses Danny.
A photographer gets Danny into Berlin for a story. He finds Federica cleaning up the rubble. Danny gives out cigarettes, and paint spills on his uniform. Federica gets his clothes cleaned while he takes a bath. Stieber (O. E. Hasse) tells Danny that he counts the flights for the Russians, who do not trust the statistics printed in the newspapers. He gives Danny clothes to wear, as the tailor shop is closed. Federica and Danny take a train to the Russian sector. In a restaurant they meet Hank and Gerda (Bruni Lobel). Hank gives Gerda orders and says that the Germans are authoritarian and have a father complex. Danny says that Hank is like that too. Hank argues but changes his behavior toward Gerda. He tries to explain democracy to her. Hank follows a man with a limp and calls him Felix. He was a prison guard and beat Hank, who gets revenge for his bad treatment. Danny stops Hank from beating him. Military Police arrive, and Danny runs away with Federica into the Russian sector. At the border she says that Danny is her husband. The boundary is disputed, and they escape. Danny wakes after 3 in the morning. Federica has electricity from 3 to 5 and is ironing his uniform. She realizes that Danny loves her.
Danny returns to his plane but gets time off. Hank shows Danny proof that her husband was in the SS. Federica admits she lied to make him sympathetic but says they have to survive. Danny walks away, but he comes back later.
Danny asks permission to marry a German. Hank tells Gerda how people of different nationalities live in New York City. Federica gets a letter. Danny learns he is leaving on Friday. Danny talks with Federica through a fence. Fog slows down flights. Danny is on a plane that has a burning engine and has to make an emergency landing. Hank uses radar and gives them landing instructions by radio. They land safely.
Danny finds Federica in Berlin. Hank tells Gerda they are going to a wedding. She argues with him about her rights. Federica gives Stieber a letter to mail. Stieber opens it and reads how she plans to meet her lover in America. Danny shows her the letter and lets Hank read it. Danny walks away. Gerda follows him and says she is staying in Germany to help make it better. Hank tells Danny that he has switched to permanent duty, and he speaks German. Danny says goodbye.
This post-war drama depicts the famous Berlin airlift and the desperate plight of the Germans trying to recover while being occupied by the armies of four nations. An American with authoritarian tendencies learns about democracy by teaching it to his German girlfriend.