A serial-killer frightens Paris by phoning young ladies at night, telling them insults about their lives. Minos, as he calls himself, wants to prevent the world from free women and he targets at first these ones. Commissaire Letellier is given the investigation and he has hard work with the maniac.

In this action comedy the French boxer Jo Cavalier is charmed on the train to Berlin for the Olympics in Hitler's Germany by the little boy Simon Rosenblum who asks his autograph; when it turns out his adorable young fan is a Jewish orphan in danger of persecution, he risks his one shot at Olympic glory to save Simon and his family, helped only by a German officer-gentleman who became his friend in World War I, by an adventurous escape to Switzerland, Nazi troops on their heals and braving impossible odds in roller coaster-style.

Since the suicide of his wife, Jacques Loursat has gone downhill. Estranged from his daughter, his lawyer's pratice in ruins, he consoles himself with drink. One night he is woken by a gunshot and catches sight of a young man fleeing the house. Isabelle, his daughter, claims to know nothing about it, even when he finds the body of a young man. Isabelle hangs around with a gang of spoiled young people who have no shortage of money, and is in love with Joel, an ambitious boy involved in drug dealing. Antoine, from a more modest background, is in love with her. When the police start investigating Joel's murder, Antoine becomes the ideal suspect.