Diabolique
Les Diaboliques (original)
Before Psycho, Peeping Tom, and Repulsion, there was Diabolique. This thriller from Henri‑Georges Clouzot, which shocked audiences in Europe and the U.S., is the story of two women—the fragile wife and the willful mistress of the sadistic headmaster of a boys' boarding school—who hatch a daring revenge plot. With its unprecedented narrative twists and terrifying images, Diabolique is a heart-grabbing benchmark in horror filmmaking, featuring outstanding performances by Simone Signoret, Véra Clouzot, and Paul Meurisse.
Starring Véra Clouzot, Simone Signoret, Jean Brochard, Pierre Larquey, Michel Serrault, Paul Meurisse, Charles Vanel, Yves-Marie Maurin, Georges Poujouly, Thérèse Dorny
It's a drama and horror movie, and has a rating of 8.1 out of 10 from Imdb which is very high for this kind of movie.
Watch it here
Not found streaming from Ireland.