During WW2, as the German forces rapidly advance toward the French coast, naive French country girl Babette makes her way to the coastal town of Dieppe. She is looking for work as a house maid at Madame Fernande's cat-house. Unfortunately, Madame Fernande and her girls are about to be evacuated to England by a French boat. Having no other choice, Babette decides to follow Madame Fernande to England. In London, Babette makes her way to the headquarters of the Free French Forces to make herself useful. She is hired as a maid, kitchen helper, housekeeper and eventually switchboard operator. Babette isn't too bright but she catches the eye of young and handsome French lieutenant Gérard De Crécy-Lozère. His aristocratic parents live in France but he is in London fighting under General De Gaulle, assigned to wartime intelligence. Babette also catches the eye of British Intelligence colonel Fitzpatrick who is astonished at the similarity between Babette and Hilda. Hilda is German General Franz Von Arenberg's old flame. The German General is an important man at the German Army HQ on the French coast. Therefore, British and French Intelligence figure they could kidnap General Franz Von Arenberg if they could parachute Babette in occupied France and substitute her for Hilda. They convince Babette to play along and they give her the standard training in a school for clandestine agents. They also send along French lieutenant Gérard De Crécy-Lozère to contact the French Resistance and aid Babette in her mission. Unknown to all of them is the fact that General Franz Von Arenberg is closely monitored by the local Gestapo under the command of Obersturmführer 'Papa Schulz' who suspects the German General is disloyal to the Nazi cause. After Babette and Gérard are parachuted into France at night, they get separated. Gérard meets with the local Resistance and Babette is befriended by various Germans, including General Von Arenberg, SS officers and Gestapo's 'Papa Schulz'. No one suspects Babette to be a British agent. When she is recruited by Gestapo's 'Papa Schulz' to work for him, in his obsessive quest to entrap General Von Arenberg, a series of comedic mix-ups, mishaps, double-deals and back-stabs ensues.