Diabolique

Diabolique (1955) is a thriller, mystery directed by Henri-Georges Clouzot rated 7.9/10.

The cruel and abusive headmaster of a boarding school, Michel Delassalle, is murdered by an unlikely duo -- his meek wife and the mistress he brazenly flaunts. The women become increasingly unhinged by a series of odd occurrences after Delassalle's corpse mysteriously disappears.