A doctor invites his relatives to his castle, all the while planning to murder them when they arrive. However, when he himself is murdered, the relatives know they have to find the killer before he gets all of them.
| Directing | Santos Alcocer | Director |
| Writing | Santos Alcocer | Screenplay |
| Writing | Enrique Jarber | Novel |
| Production | Santos Alcocer | Producer |
| Production | María Ángel Coma Borrás | Producer |
| Sound | Ramón Femenías | Music |
| Camera | Emilio Foriscot | Director of Photography |
| Editing | Rosa G. Salgado | Editor |
| Art | Teddy Villalba | Set Decoration |
| Production | Gerardo Mendiburu | Production Manager |
| Production | Ángel Rosson y Rubio | Production Manager |