DIAL M FOR MURDER is a minimalistic talk ‘n murder from our boy Alfred Hitchcock circa 1954. It doesn’t have the same “all in one shot” camera gimmick as ROPE (which was 6 years earlier), but it’s similar because 95% of it takes place in one apartment where an arrogant guy thinks he can get away with murder and an inquisitive guy tries to outsmart him and figure out what went down.
The attempted mastermind is Tony (Ray Milland), whose wife Margot (Grace Kelly) has an American boyfriend named Mark (Robert Cummings), so that would be the motive. Margot and Mark have called it off and tried to keep it a secret, but Tony has known for a long time and has put alot of work into staking out an old college acquaintance named Swann (Anthony Dawson) so he can find dirt on him and blackmail him into doing a murder.