Les Diaboliques (French pronunciation: [le djabɔlik]), released as Diabolique in the United States and variously translated as The Devils or The Fiends, is a 1955 French black-and-white thriller feature film directed by Henri-Georges Clouzot, starring Simone Signoret, Véra Clouzot and Paul Meurisse. It is based on the novel Celle qui n'était plus (She Who Was No More) by Pierre Boileau and Thomas Narcejac. The story blends elements of thriller and horror, with the plot focusing on a woman and her husband's mistress who conspire to murder the man; after the crime is committed, however, his body disappears, and a number of strange occurrences ensue.

Clouzot, right after finishing Wages of Fear snatched the screenplay rights from master of suspense director, Alfred Hitchcock. This movie helped inspire Hitchcock's Psycho.[citation needed] Robert Bloch himself, the author of novel "Psycho", has stated in an interview that his all-time favorite horror film is Diaboliques.

Now considered a classic of the horror genre and film in general, Les Diaboliques ranked #49 on Bravo's 100 Scariest Movie Moments.

Based on a novel by the same authors who were also adapted for Vertigo, this is a dark, scary, and deadly serious thriller with oodles of suspense and a heart-stopping ending. The plot is laid out simply, and it progresses quickly; the tension is soon amped up as the mystery deepens. There's no hint of irony or comedy in its tone; the brutal events and actions are depicted with unflinching solemnity. Its supernatural qualities grow as the story unfolds, but the ending ties all the loose ends up and ends on a distinctly depressing note. Even the final scene, returning some of the mystery with a hint of ambiguity, cannot lift this film's spirits up.

I found the macabre tone a bit off-putting at times, but its manner of storytelling and horrific tale cannot be overlooked. The last five minutes or so are truly terrifying, and I would've liked more of that pure horror throughout, but the use of suspense is just as effective. The slow psychological breakdown of the main character is portrayed well, if not too subtly, and the horrific climax is the perfect scene to top it off. I also would've liked a bit more style and expressionism to the camera work and production design, as they utilize the same brutal realism that the plot does, but they are effective nonetheless.

A must-see for fans of Hitchcock and horror nuts especially.