On the run from international police, Special Agent Lemmy Caution arrives in the South of France and soon becomes embroiled in a scheme with the infamous gangster Siegella. Whilst seeming to co-operate with the underworld boss, Lemmy is secretly acting for the FBI, and intends using Miranda Van Zelden, a wealthy heiress, as bait to trap a gang of crooks and put an end to Siegella's exploits...

The renowned theatre manager, Paul Rémy, is accused by his general secretary Andrieux of having killed his partner. On the advice of his wife Mona, Paul goes into hiding in a psychiatric hospital to escape from the police. But Andrieux seduces Mona who then turns against her husband.