And once you've watched them both, you'll know why. While Alfred Hitchcock's "Psycho" may have been dealing with extra thematic material beneath its horrific surface, providing additional dimensions that the French film didn't have, "Diabolique" (or "Les Diaboliques" as it's known in France) is a thriller whose atmosphere and sense of mystery equal that of the great Hitchcock classic. The same dark, threatening black and white cinematography and bizarre, macabre goings-on of "Psycho" meet their French counterpart in "Diabolique", much to the viewer's delight. And while "Psycho" gave the world perhaps the most memorable scene revolving around a shower, "Diabolique" presents the most memorable scene[s] connected with a bathtub. More outstanding than any other bathtub scenes, in my opinon, including the ones from "The Shining".
From the tension before the murder to the mysteries that arise afterwards, the suspense mounts to an eerie climax that remains one of the Cinema's most exciting, whether you predicted it or not. If you weren't expecting it, it will truly be a frightening and confusing (in a good way) surprise. If you successfully foretold it, it will satisfy your suspicions and still captivate your attention.
The only thing that seems sub-par about the film is the police detective's role in the incidents during the climax and after. You may wonder why he didn't arrive on the scene earlier, or whether he could have prevented certain events from occurring. It seems awkward that he shows up when he did and knows all about what just happened. One gets the idea that perhaps French Production Codes of some kind had an effect on the plot at this point, giving the ending a somewhat forced and artificial flavor.
