A lot of robbed jewels is out in the nature, and no one knows where it is hidden. Possibly the robber's girlfriend knows. When she is out of prison, and returns to her cabaret show in Montparnasse, the police is after her to discover her secret. But the police is not alone. The girl from Pigalle will discover love, and lose it, while the undercover cop will discover the jewels, lose them, and find love.