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.
| Actor | Role |
|---|---|
 Anne VernonJeanne Masson | Jeanne Masson |
 Maurice RégameyInspector Pierre Leblanc | Inspector Pierre Leblanc |
 Aimé ClariondCortedani | Cortedani |
| AAlfred ArlaisNot listed | Not listed |
 René BlancardInspector Martial | Inspector Martial |
 Yvonne DanyNot listed | Not listed |
 Gil DelamareNot listed | Not listed |
 Jo DestPoliceman | Policeman |
| PPierre GoutasMobster | Mobster |
 François JouxDoctor | Doctor |
 Jean-Jacques LécotMobster | Mobster |
 Marcel MelracInspector | Inspector |
| SSimone MichelsGaby | Gaby |
 Robert MoorChemist | Chemist |
 François PatriceRoger Masson | Roger Masson |
| RRaymond RaynalRaoul | Raoul |
| NNicole RicheNot listed | Not listed |
 Pierre SergeolAlbert | Albert |
 Jean-Marc Tennberg'Dédé le fada' | 'Dédé le fada' |
| MMarc ValbelBrasier | Brasier |
 André ValmyCommissioner Didier | Commissioner Didier |
 Charles VissièresThe witness | The witness |