1.   What is the significance of the Dictaphone in Double Indemnity?

The office Dictaphone was a precursor to the reel-to-reel (and later the cassette) tape recorder that appears often in business offices in older movies. The Dictaphone allowed users to start, pause, restart and stop speech which was recorded onto a cylinder disc for later playback. The film’s opening scenes set up the subsequent narration as a confession recorded into a Dictaphone as a way of grounding the voice-over narration in reality: after all, Walter would otherwise have to be narrating from the grave (an experimental choice that director Billy Wilder would actually use in Sunset Boulevard). The Dictaphone also allows Walter’s confession to continue without interruption which would have been the case if Keyes had been in the office when he gets there. The essential significance of the Dictaphone confession, however, is that Walter’s narration is as terse and singularly focused as it has been the other times we’ve seen him use the device, thus providing insight into his psychological makeup as a murderer.

2.   What are the elements of film noir on display in Double Indemnity?

Double Indemnity fused many elements together to become perhaps the first iconic example of film noir genre. It uses high-contrast, low-key lighting, complemented by the use of venetian blinds as a filter. It features a passive, weak-willed protagonist who falls prey to a scheming, predatory woman ("femme fatale"), and a narrative that revolves around a complex murder plot. The film's voice-over narration and flashback structure also influenced numerous films noir to follow, as did its moody, dark representation of urban Los Angeles.

3.   What evidence is there to support the contention that the real love story of Double Indemnity takes place between Walter and Keyes?

No love is lost between Walter and Phyllis, because no love ever really existed. The relationship between those two is all passion: first desire for each other, then desire to kill, then the desire to turn on each other. In other words, no romance exists in the passion that Walter and Phyllis run on. No romance exists between Keyes and Walter, either, but there is genuine and deep respect and affection for each other; something that is never displayed by Walter or Phyllis toward the other. That respect even extends to the loyalty they manifest toward each other. Walter is so respectful of Keyes that his loyalty extends to confessing directly to him; he has no respect for the cops. Needless to say, no loyalty whatever can be found in his relationship with Phyllis.

4.   How do notions of debt, payment, and insurance factor into the story?

As a story set in and around an insurance company, Double Indemnity ties notions of payment and insurance to its narrative in a figurative sense. As a salesman, Walter is necessarily trying to solicit payment from potential clients; as a scheming housewife, Phyllis cravenly desires the payout of the accident insurance policy. Walter "thinks with [Barton's] brain," in order to pull off the perfect crime: essentially an informal insurance policy against the possibility that the plot will be discovered. Phyllis keeps Nino around as insurance so that she has multiple men to manipulate and insulate her from suspicion. When Phyllis makes one last-ditch effort to convince Walter she loves him, he says, "Sorry baby, I'm not buying," suggesting that her currency is worthless to him.

5.   How does the image and metaphor of the train symbolize the plot between Phyllis and Walter?

Walter tells Phyllis early on that their plan must be perfect "straight down the line," which begins a metaphor about trains and railways that continues over the course of the film. According to this metaphor, Walter and Phyllis's joint scheme makes them passengers on a train, which they must ride to its final destination, which Walter realizes too late is the cemetery. The metaphor also of course refers to the fact that the plot to kill Mr. Dietrichson takes place in and around a train. Walter makes one last attempt to "get off" the train at the end of the film when he says, "Two people are going to ride to the end of the line, all right. Only I'm not going to be one of them. I've got another guy to finish my ride for me," until fate intervenes and Phyllis shoots him.