Cast: Ray Miland, Grace Kelly, Robert Cummings.
There is little left to say about Alfred Hitchcock, the cinematic pioneer. Amongst his many accomplishments, he is remembered for one of the first full color 3D movies: Dial M for Murder , which remains a timeless classic until today. Penned as a novel by Agatha Christie, the cinematic version retained the intrigue of the book, with a perfect casting is one of those movies that you can watch again and again.
Tony Wendice (Ray Milland) is a former tennis player who married Sheila (called Margot in the movie, played by Grace Kelley) partly for her money. To please his wife, he has given up tennis and now has a job selling sports equipment. Sheila had a brief affair with relationship with Max Halliday (called Mark Halliday in the movie, played by Robert Cummings), a crime writer for American TV.
Tony is aware of the affair, and is now afraid that the affair may recur, since Sheila does still meet Max- though as a friend. In case of a divorce, he would receive very little of his wife's considerable wealth (guess they didn't have a pre-nup agreement). However, in case of Sheila's death, he would inherit the whole kahuna. So for one year, Tony has meticulously planned Sheila's murder. He steals one of her letters to Max, sets himself up as a anonymous blackmailer her handbag containing one of Max's letters, and even assumed the role of an anonymous blackmailer extorting money from Sheila for the letter.Tony withdraws small amounts of money from his bank for a year, collecting £1,000 in old one-pound notes. He additionally blackmails an old classmate- C A Swann, into murdering Sheila.Only things go horribly wrong: Instead of being killed, Sheila successfully defends herself from Swann's attack, the latter actually dropping dead in the skirmish.Thinking on his feet, Tony turns this setback around- he leaves behind manufactured clue after clue for the police to find, all making it appear transparent that Swann was Sheila's blackmailer, and she killed him in a rage while trying to get her old love letters back
The Inspector arrives at that moment, allegedly to ask Tony about the money he has been spending lately. This is when Max discovers Tony's bag filled with the remaining one pound notes (remember those?) Pressed for an answer, Tony manages a final impromptu lie in front of both Max and the police: He tells them this is the money Sheila had ready when she met Swann but that she changed her mind and killed him instead of paying him off- boy this guy is smooth.
Then the inspector, who has not given up the case yet but who pretends he has, uses his final trick: He says good-bye and deliberately takes Tony's raincoat instead of his own. Now Tony's key to the flat is in the pocket of his raincoat, so on returning to his flat some time later he realizes that he cannot get inside. He notices that he is wearing Inspector Hubbard's raincoat and goes off to the police station to exchange it. Meanwhile, Hubbard has brought Sheila to the flat.
Her key—actually Swann's—does not fit into the lock, so she cannot open the door. What Hubbard wants to find out is if she knows the hiding place under the stair carpet. She does not, so that clears her of any suspicion. Some time later, Tony comes back. When he takes the key from under the stair carpet he gives himself away.