The mysterious vigilante Milton has warned Scotland-Yard of his intention to kill the lawyer Maurice Meister who is the cause of his sister's suicide. Police and detectives watch over the lawyer's home, but on the day and at the appointed time Meister is murdered.
| Actor | Role |
|---|---|
 Jean GallandLawyer Maurice Meister | Lawyer Maurice Meister |
 Raymond RouleauInspector Berry | Inspector Berry |
| MMarion DelboCora Milton | Cora Milton |
 Janine MerreyMary Lengley | Mary Lengley |
 Paul OettlyDoctor Lomond | Doctor Lomond |
 Maurice RémyInspector Bliss | Inspector Bliss |
 FernandelSam Hackitt | Sam Hackitt |
| AAlfred ArgusNot listed | Not listed |
| CCamille CorneyColonel Davis | Colonel Davis |
| JJean GuiltonNot listed | Not listed |
 Marcel HerrandJohnny Lengley | Johnny Lengley |
 Georges PaulaisThomas, detective | Thomas, detective |