The setting is the French Riviera where the widow Georgina (Martine Carol) presides over her family of two teen-age children and a dotty father-in-law. In addition, there is the visiting student from Germany who happens to be her secret lover, and their gardener, the father of the murder victim. An inspector (Michel Galabru) has to ferret out the clues that will eventually lead him to the killer in this odd group of people -- though the audience is likely to be two steps ahead of him.

Source : allmovie.com