One of two plays that Hitchock ever adapted for the big screen (Rope was the other), Dial M For Murder isn't one of Hitchcock's true great flims, but it is a very entertaining piece of work.
It relvolves around an elaborate, and perhaps it's TOO elaborate, plot by ex-tennis player Tony Wendice (Ray Milland) to have his wife Margot (played by the exquisite Grace Kelly) killed after she's had an affair with Mark Halliday (Robert Cummings).
Given time constraints, relatively little re-writing was done for the screen which meant that the London setting was left intact as were the British nationality of the characters. This does mean however that the film is very heavy on dialogue, and it does sometimes betray the undoubted cleverness of the plot as being all a little shallow.
Where Hitchcock can excel though is in manipulating the audience's sympathies. Despite her extra-marital affair, we naturally hold our affections with Margot, after all who would want to kill Grace Kelly, but when the action switches in the second half of the film, who hasn't watched and hoped that Tony Wendice, a man who after all is allowing his wife to be executed for a crime she didn't commit, does indeed manage to outwit and outsmart his pursuers? (a trick Hitchcock had used before and would use again).This is helped no end by Millard's performance, at once charming but frightening, funny but reptillian and he's probably the best thing in the movie.
The script is not a great one, it has to be said, but in Hitchcock's expert hands it translates into a great film.