 In Paris s Montmartre district, everyone knows Bob, a well-dressed compulsive gambler. He s generous, moralistic, drives a two-toned convertible coupe, lives in a swank apartment, and has the respect of the police. But he s on a losing streak, and even when he hits it big at the track, he loses at the Deauville casino. When he learns that the casino keeps a fortune on Grand Prix weekend, he plots a robbery. Subplots trace a seemingly innocent coquette s social climb and the greed of a croupier s wife who betrays the thieves.