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.