Fred Barker, an unmarried American who remained in France after heroically defending the country during the Second World War, runs the perfume factory in Grasse of his friend Carlo Ferelli, whose life he saved during the conflict. Fred has since adopted a little girl, Cathy. One day, he receives a visit from Félix Mercier, an old man who informs him that he has taken Cathy into his custody and that he will return her to him when Fred finds his granddaughter Hélène, a 17-year-old teenager who accuses the factory of being a front for white slavery. Fred, dumbfounded, sets out to find Hélène, so he can quickly get Cathy back.