In September 1942, fighter pilot Jimmy Briggs is shot down over France. Hiding in a village school, he overhears a discussion between resistance worker Ann-Marie Poitiers, codename 'Nina', who has fled from Paris after the resistance meeting she was attending to act as interpreter was broken up, and the local resistance led by codename 'Vincent'. Vincent's instinct is to shoot Nina as a security risk, and, doubting his story, Jimmy as a probable German infiltrator. His radio operator, Robespierre, is unhappy with this and seeks advice from London, who give orders to return Jimmy and Nina to Britain. With the Germans already starting to search the village, Jimmy, Nina and Vincent are able to escape.