Diabolique grabs you from the start and never lets you go. It is at once mysterious and intense, but it continues to excite because the underlying reason for the fear shifts throughout the film. The tension in the beginning is a result of the way M. Delassalle abuses his wife and mistress (to the point where they console each other). In the middle it is caused by the imminent murder of M. Delassalle by the two women. And for the last half of the movie, the tension reaches a peak because M. Delassalle's dead body has gone missing.
This movie is perfectly crafted, from theme to execution. Watching this movie is one of those rare treats in cinema where every aspect of filmmaking comes together, and without flaw. The lighting and cinematography work on a thematic level, with ubiquitous bars of lights and shadows, stairways and columns, visually imprisoning Christina, the wife, to reflect how her marriage traps her. The dialogue and acting are expressive, yet subtle. They are meaningful, layered, and nuanced, yet never unnatural. The story is a treasure to unravel; it is clever and funny in more ways than one. You can watch this movie once and think it is amazing, but you can also watch it again and get a completely different picture (still thinking it's amazing).
The story, written by Boileau and Narcejac, felt more contained and thought-out than Vertigo, which they also wrote. That being said, the story gets a bit excessive and ludicrous in the planning of dirty deeds. And there is a force of good and order at the end--perhaps the creators were too unsure of themselves to let the bad guys win, much like Kurosawa in Rashomon? Either way, this movie is required viewing for lovers of Hitchcock. It rivals some of his best and surpasses most of the rest; and it also works really well as a partner piece for Vertigo. And as the original poster tagline says, see it and be amazed by it.IMDb link: http://imdb.com/title/tt0046911/