The brother of Jeanne Masson, a young nightclub singer, has been murdered by Brasier, a criminal who pretends to be a respectable man. Jeanne has resolved to avenge her brother but she just cannot take action herself. The way she finds is to ask police detective Pierre Leblanc to help her do it. Pierre gives his agreement and starts following the trail. He soon finds out that Brasier belongs to a gang whose boss, Cortedani, has ordered the murder.

Anne Vernon
Jeanne Masson

Maurice Régamey
Inspector Pierre Leblanc

Aimé Clariond
Cortedani
Alfred Arlais

René Blancard
Inspector Martial

Yvonne Dany

Gil Delamare

Jo Dest
Policeman
Pierre Goutas
Mobster

François Joux
Doctor

Jean-Jacques Lécot
Mobster

Marcel Melrac
Inspector
Simone Michels
Gaby

Robert Moor
Chemist

François Patrice
Roger Masson