This Man Must Die French Que la bte meure , American title The Beast Must Die, is a 1969 French and Italian thriller film directed by Claude Chabrol. The story is based on a 1938 novel by Cecil DayLewis, writing as Nicholas Blake, The Beast Must Die. The film had a total of 1,092,910 admissions in France.
The police investigation is fruitless. Charles thinks the guilty party may run a garage, since there is no record of a car going in for repairs. By chance, while pursuing this hunch, he discovers that actress Hlne Lanson was the passenger in a car that was damaged on the day of his sons death. Adopting a pseudonym, he seduces her and discovers that the driver was her brotherinlaw Paul Decourt. He arranges a trip with Hlne to visit her sisters family in Brittany.Charles discovers that Paul is detestable, cruel to his wife and hated by his teenage son Philippe. He has conflicting thoughts as to whether or not he will kill Paul. He rescues him from a clifffall. Phillipe confides to Charles his own desire to kill his father. ........
Source: Wikipedia