Marianne Jannetier, a well-to-do Parisian, engaged to Andre Benoit, a high-ranking government official, flee the city when the goose-stepping German storm troopers arrive. After her mother dies on the road to Bordeaux as a result of German bombing, she returns to Paris and joins the underground movement. Nicholas Jordan, an American member of the RAF, stranded in Paris after the evacuation, is also working with the Paris underground. Marianne kills her former fiancé, a pro-German informant, for the traitorous state papers he is carrying, and she and Jordan try to flee through a French seaport.