When Monsieur Crauqual, the supervisor, is found hanging, all wonder why this rather rich person decided to kill himself. And when a pupil is found hanging too, François and his friends decide to investigate. They are certain there is a killer within the walls of Collège François 1er and determined to prevent him from going on running wild.
| Production | Michel Lesay | Producer |
| Directing | Maurice Labro | Director |
| Writing | Maurice Labro | Screenplay |
| Writing | Francis Didelot | Novel |
| Art | Eugène Piérac | Set Decoration |
| Camera | Pierre Petit | Director of Photography |
| Editing | Robert Isnardon | Editor |
| Sound | Claude Arrieu | Original Music Composer |
| Sound | Yves Baudrier | Original Music Composer |
| Production | Yvan Noé | Production Manager |
| Writing | Yvan Noé | Screenplay |