Two French journalists become embroiled in a criminal plot in New York City involving a disappeared United Nations diplomat.
Lise is bored with her parents and gets a job as a waitress. She meets a sailor, Fausto, who leaves her to escape from the police. Nevertheless, she gives birth to a baby who dies shortly afterwards. Distraught, she steals a parentless child from a maternity hospital. Arrested and tried, she is acquitted, only to find Fausto innocent.
Just released from prison after serving a six-month sentence, Fernand Bastia goes into hiding. He has indeed double-crossed his gang by keeping part of the product of a robbery for himself. Thanks to his sister Marcella, Fernand has taken refuge in a small circus where she works. There, he falls in love with Gina but also arouses the jealousy of Quedchi, a fairground stall-holder who has seen him hiding the stolen money. After a while, Fredo Riccioni, the boss of the gang and his men, manage to trace him...
In Paris, Bob Montagne is practically synonymous with gambling -- and winning. He is kind, classy and well-liked by virtually everyone in town, including police inspector Ledru. However, when Bob's luck turns sour, he begins to lose friends and makes the most desperate gamble of his life: to rob the Deauville casino during Grand Prix weekend, when the vaults are full. Unfortunately, Bob soon learns that the game is rigged and the cops are on to him.