Marie-Chantal travels by train to her cousin's place to spend a winter holiday, when a stranger entrusts her with false jewels that contain a virus powerful enough to destroy all humankind.
| Writing | Claude Chabrol | Writer |
| Writing | Yves Christian Fournier | Scenario Writer |
| Directing | Claude Chabrol | Director |
| Writing | Daniel Boulanger | Dialogue |
| Writing | Claude Chabrol | Scenario Writer |
| Editing | Jacques Gaillard | Editor |
| Camera | Jean Rabier | Director of Photography |
| Editing | Monique Fardoulis | Assistant Editor |
| Production | Georges de Beauregard | Producer |
| Production | Pierre Gauchet | Producer |
| Sound | Gregorio García Segura | Music |
| Sound | Pierre Jansen | Music |
| Art | Guy Littaye | Production Design |
| Costume & Make-Up | Carmen Fatum | Makeup Artist |
| Production | Abderhamane Benkirane | Assistant Production Coordinator |
| Production | Gérard Beytout | Unit Production Manager |
| Production | René Demoulin | Production Director |
| Production | Pierre Gauchet | General Manager |
| Production | Colette Roy | Production Secretary |
| Production | Roger Scipion | Production Supervisor |
| Directing | Claude Bakka | Second Assistant Director |
| Directing | Lucio D'Attino | Second Assistant Director |
| Directing | Philippe Fourastié | First Assistant Director |
| Directing | Mohamed Osfour | Second Assistant Director |
| Directing | Alexis Poliakoff | Second Assistant Director |
| Sound | Jean-Claude Marchetti | Sound Mixer |
| Sound | Guy Odet | Sound Engineer |
| Sound | Guy Villette | Sound Mixer |
| Camera | Paul Bonis | Assistant Camera |
| Camera | André Dino | Still Photographer |
| Camera | Claude Zidi | Camera Operator |
| Editing | Catherine Bernard | Editorial Services |
| Sound | Pierre Colombier | Musician |
| Sound | André Girard | Conductor |
| Directing | Suzanne Faye | Continuity |
