If Double Indemnity is short on any aspect which defines a good film-noir, tension is certainly not one of them. Director Billy Wilder manages to keep the tension as thick as syrup through the duration of the movie, despite the fact that the audience is, from the start, already aware of the murder that has taken place, as well as the main protagonist Walter Neff’s role in it and his impending doom. Wilder makes this clear, as Neff, obviously mortally wounded in the opening scene, tells the entire tale in flashback after his confession – “I killed Dietrichson – me, Walter Neff…”. One of the more interesting manners in which he does this is through Neff’s relationship with his friend and the firm’s Claim Manager Burton Keyes.
The relationship between the two men is key to creating and maintaining the tension and suspense throughout the movie. While Neff was sure he knew the system inside out, well enough to be able to pull off the deed without getting caught, the only man he was afraid of was none other than Keyes, whose “inner man” unerringly sniffed out false claims.
The most obvious device that Wilder uses between Neff and Keyes is the lighting of cigarettes/cigars. In key points throughout the film where Keyes appears to be close to cracking the case but comes up short, he always has trouble lighting up his cigar, and Neff lights it up with a wooden match. In the final scene, however, when Neff no longer has things under control, Keyes reciprocates the favor.