Jean Boucheron the cat burglar is the darling of the Montmartre whores--and catches the eye of slumming socialite Zelia de Chaumont, who decides to "reform" him. A complication is his lovely young ward Odile... murder and a grand courtoom scene ensue.

A government agent is returning from France with secret blueprints that were stolen from his government. On the train ride home, thieves break into his compartment and murder him.