The brave Monsieur Breloque has a friend, Pierre Martel, a private detective. When the latter asks him to replace him for a while, Breloque, although having no competence in the matter, accepts. He anticipates adventures and misadventures but also happy surprises.
| Actor | Role |
|---|---|
 Lucien BarouxMonsieur Breloque | Monsieur Breloque |
 Marcel SimonCount of Brazeuil | Count of Brazeuil |
 Junie AstorFrancine | Francine |
 Gabrielle DorziatBaroness Granger | Baroness Granger |
| FFoun-SenThi-Hou | Thi-Hou |
 André BervilDetective Pierre Martel | Detective Pierre Martel |
 Jean BrochardNot listed | Not listed |
 Rivers CadetNot listed | Not listed |
 Pauline CartonNot listed | Not listed |
| PPaul CastanNot listed | Not listed |
| RRaymond GalleThe son | The son |
 Claire GérardNot listed | Not listed |
 Pierre JuvenetNot listed | Not listed |
 Charles LemontierNot listed | Not listed |
 Jean PeyrièreNot listed | Not listed |
 Marguerite PierryHermance Piegeois | Hermance Piegeois |
 Suzy PiersonCountess of Brazeuil | Countess of Brazeuil |
 Elisa RuisNot listed | Not listed |
| RRobert SellerNot listed | Not listed |
 André SiméonNot listed | Not listed |