Marc Elbichon, a novice private sleuth, is investigating a wave of assassinations bearing a particular characteristic: the perpetrator, dubbed the "telephone killer" always strangles his female victims with a telephone cord.
| Directing | Jean-Pierre Vergne | Director |
| Writing | Didier Bourdon | Writer |
| Writing | Seymour Brussel | Writer |
| Writing | Bernard Campan | Writer |
| Writing | Pascal Légitimus | Writer |
| Writing | Jean-Pierre Vergne | Writer |
| Production | André Djaoui | Producer |
| Sound | Gabriel Yared | Original Music Composer |
| Camera | Robert Fraisse | Director of Photography |
| Editing | Nicole Berckmans | Editor |
| Production | Laurence Lustyk | Casting |
| Art | Daniel Budin | Production Design |
| Costume & Make-Up | Monique Perrot | Costume Design |
| Costume & Make-Up | Sidonie Constantien | Key Hair Stylist |
| Costume & Make-Up | Jacky Reynal | Key Makeup Artist |
| Sound | Paul Bertault | Sound Re-Recording Mixer |
| Sound | Jean Duguet | Sound Effects Editor |
| Sound | Jean-Pierre Lelong | Sound Effects Editor |
| Sound | Jacques Lévy | Sound |