- Directors: Billy Wilder
- Producers: Buddy G DeSylva, Joseph Sistrom
- Writers: Novella, James M Cain, Screenplay, Billy Wilder, Raymond Chandler
- Genres: Crime, Film-Noir, Thriller
- Actors: Fred MacMurray, Barbara Stanwyck, Edward G Robinson
Walter Neff (MacMurray) is a successful insurance salesman for Pacific All-Risk returning to his office building in downtown Los Angeles late one night. Neff, clearly in pain, sits down at his desk and tells the whole story into a Dictaphone for his colleague Barton Keyes (Robinson), a claims adjuster.
He first meets the sultry Phyllis Dietrichson (Stanwyck) during a routine house call to renew an automobile insurance policy for her husband. A flirtation develops, at least until Neff hears Phyllis wonder how she could take out a policy on her husband’s life without him knowing it. Neff realises she intends to murder her husband and wants no part of it.
Phyllis pursues Neff to his own home, and persuades him that the two of them, together, should kill her husband. Neff knows all the tricks of his trade and comes up with a plan in which Phyllis’s husband will die an unlikely death, in this case falling from a moving train. Pacific All-Risk will therefore be required, by the ‘double indemnity’ clause in the insurance policy, to pay the widow twice the normal amount.
Keyes, a tenacious investigator, does not suspect foul play at first, but eventually concludes that the Dietrichson woman and an unknown accomplice must be behind the husband’s death. He has no reason to be suspicious of Neff, someone he has worked with for quite some time and admires.
Neff drives to his office where he dictates his full confession to Keyes, who arrives and hears enough of the confession to understand everything. Neff tells Keyes he is going to Mexico rather than face a death sentence but collapses to the floor before he can reach the elevator.