In Heidelberg, during the tense years after World War II when the city sits under Allied occupation, Captain Henri Rochard, Cary Grant, is given a delicate mission: identify and recruit a gifted lens maker named Schindler. He is paired with American Lieutenant Catherine Gates, Ann Sheridan, as his driver, a setup that immediately stirs friction between two people who have clashed before. The only available transport is a motorcycle, and due to Army rules, Catherine must steer the bike while Henri rides in the sidecar. What should be a straightforward assignment quickly becomes a test of patience as their frequent squabbles spill into the open and the two finally reach their destination: Bad Nauheim.
At the hotel, Catherine battles a painful back and, in a rare moment of comfort, allows Henri to offer a back rub. She nods off, and when she wakes, Henri tries to slip away. The exterior door handle has failed him once again, trapping him in the room. He spends an awkward night in a chair, while Catherine awakens convinced there’s more to the story. Only later do they discover that the innkeeper’s wife had secretly replaced the door knob, turning a misfortune into a comic, revealing truth about the night’s events. The innkeeper’s wife explains everything, but not before Henri has to improvise a daring escape from the ledge outside the window, a moment that cements the precarious balance of their working relationship and mutual suspicion.
Henri then goes undercover to locate Schindler, who has fallen into the black market trade. He insists that Catherine stay out of it and even tells her to pretend she doesn’t know him if she crosses paths with him. The market is raided by authorities, and Henri is arrested along with others. While in jail, he asks Catherine to vouch for his identity, but she adheres to his earlier demand not to reveal they know each other. In a separate turn of luck, Catherine eventually finds Schindler, who is eager to leave Germany behind and continue his craft in France. This reunion rekindles the sense of purpose for both of them, and Catherine later apologizes to a now less-hostile Henri. When they return to Heidelberg, the two have fallen in love, their bond strengthened by shared danger and the resilience they’ve shown.
Red tape soon complicates their path to happiness. The civil ceremony must happen first so they can pursue the ceremony they each want—one with an Army chaplain for Catherine and another in a French church for Henri. To complicate matters further, and to secure Henri’s visa, they learn that he must be recognized under the War Brides Act as the spouse of an American soldier. After a series of misunderstandings born of the oddities of their situation, Henri finally receives permission to accompany Catherine, but rules and regulations conspire to keep them from spending the night together.
When the moment to board a transport ship arrives, Navy sailors balk at the idea of Henri as a war “bride.” Catherine persuades him to disguise himself as a female Army nurse in order to get aboard. The ruse works, but once underway, it’s discovered. Catherine approaches the ship’s captain, who understands the legalities of the arrangement, and at last the couple finds some privacy—though in an unlikely setting, the ship’s brig, where they can share a moment of quiet amid the larger chaos of their journey.
