Double Indemnity (1944)
An insurance representative lets himself be talked by a seductive housewife into a murder/insurance fraud scheme that arouses the suspicion of an insurance investigator.
In 1938, Walter Neff, an experienced salesman of the Pacific All Risk Insurance Co., meets the seductive wife of one of his clients, Phyllis Dietrichson, and they have an affair. Phyllis proposes to kill her husband to receive the proceeds of an accident insurance policy and Walter devises a scheme to receive twice the amount based on a double indemnity clause. When Mr. Dietrichson is found dead on a train track, the police accept the determination of accidental death. However, the insurance analyst and Walter's best friend Barton Keyes does not buy the story and suspects that Phyllis has murdered her husband with the help of another man.
Walter Neff, the Pacific All Risk Insurance Company's top salesman, returns to his office late one evening, bleeding from a gunshot wound, and dictates a memo to colleague Barton Keyes. It all started the previous May, when he stopped at a client's home for a routine renewal inquiry and instead met the client's wife, Phyllis Dietrichson. She asked about buying accident insurance for her husband without his knowledge, and Neff understood that she intended to kill him. Neff and Phyllis were soon lovers, with Neff taking charge of the killing. Initially their plan went off without a hitch, but then Neff realized that he had been played and decided to do something about it.
Alone in his company's Los Angeles offices late one evening and under some distress, insurance salesman Walter Neff dictates an inter-office memo to his colleague, claims manager Barton Keyes, about killing one of his clients, a Mr. Dietrichson. Barton suspected that Dietrichson was murdered by his wife, Phyllis Dietrichson, who was claiming the double indemnity on her husband's accident insurance policy. Walter met Phyllis innocently enough - he was dropping off auto insurance renewal papers for her husband - but quickly fell under her seductive charms. They were obvious to each other in their mutual attraction. After deducing that she was planning on killing her husband since she stated he was abusive and claiming the insurance moneys on a policy her husband would have no idea existed, Walter decided to go into cahoots with her so that he could help her craft and execute the "perfect" insurance policy, and plan and execute the "perfect" murder beyond Keyes' scrutiny, leading to them living in bliss together and with money. Beyond any slip-up in the plan, Keyes and Dietrichson's disgruntled daughter, Phyllis' step-daughter Lola Dietrichson, factored into their ability to pull off the plan successfully. Walter concludes his memo for its reason, which he considers more a confession.
Walter Neff is an insurance salesman whose life is largely devoid of any excitement and thrill. All of that changes when he meets Phyllis Dietrichson, the callous wife of a man whom she plans to murder and cash out on his accidental death claim ("double indemnity"). When he is seduced by Dietrichson into murdering her husband, the two plot a murder scheme that will not go as planned. Suddenly, the motives of each become unclear and the plan becomes further complicated when Neff's boss begins to investigate the murder.
Smooth-talking insurance salesman Walter Neff meets attractive Phyllis Dietrichson when he calls to renew her husband's automobile policy. The couple are immediately drawn to each other and an affair begins. They cook up a scheme to murder Mr. Dietrichson for life insurance money with a double indemnity clause. Unfortunately, all does not go to plan...
- 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.
It is the story of how he 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 knows she means murder 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 being thrown from a 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 is not only worried about Keyes. The victim's daughter, Lola (Jean Heather), comes to him convinced that her stepmother, Phyllis is behind her father's death because her mother also died under suspicious circumstances when she was her nurse. Neff begins to care about what might happen to Lola, both of whose parents have been murdered. It is for this reason Phyllis wants her killed because she had suspected her of murdering her parents in the first place.
Then he learns Phyllis is seeing Lola's boyfriend, Nino, behind his back. Trying to save himself and no longer caring about the money, Neff believes the only way out is to make the police think Phyllis and Lola's boyfriend did the murder, which is what Keyes now believes anyway. However, when Neff and Phyllis meet, she tells him she has been seeing Lola's boyfriend only to provoke him into killing the suspicious Lola in a jealous rage. Neff, now wholly disgusted, is about to kill Phyllis when she shoots him first. Neff is badly wounded but still standing and walks towards her, telling her to shoot again. Phyllis does not shoot and he takes the gun from her. She says she never loved him or anyone else and had been using him all along, "until a minute ago, when I couldn't fire that second shot." Neff coldly says he does not believe this new ploy. Phyllis hugs him tightly but then pulls away and looks up at him, startled that he has not responded. Neff says "Goodbye, baby," then shoots and kills her. Before leaving, he convinces Nino to not go inside because Phyllis was responsibile for trying to break up him and Lola. Neff convinces him that she still loves him and she's waiting for him to call her. Nino reluctantly agrees to call Lola and takes his quarter.
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.
 Alternate ending
Wilder shot an alternate ending to the film (to appease censors), featuring Neff paying for his crime by going to the gas chamber. This footage is lost, but stills of the scene still exist.