In Rudolph Maté's 1950 film "D.O.A." Frank Bigelow is looking for a murderer, his own. Bigelow has been poisoned and there is no antidote; he will have no more than one week to live. His urgent need to convict his murderer propels Bigelow's quest, as well as the pace of the film. It's a matter of life and death.
In a post-Hiroshima world (the film was released only five years after the tragedy of Hiroshima), society lives under a new and constant fear of nuclear fallout. While living his life unaware of danger, Frank Bigelo has been slipped a dose of "iridium", a toxin associated with radiation. He is "everyman" and his quest to track down and destroy the source of this poison could be said to represent post-War America's need to track down and destroy the source of a nuclear threat; the search for Frank Bigelo's murderer becomes the concern of every man, woman, and child who could fall prey to a similar poison from a less-personal hand.
But with typical noir cynicism we realize along with Bigalow that even if we destroy the source, it may already be too late.
While the search for a murderer creates the dramatic tension which binds this film together and propels the story forward, the individual scenes are what makes "D.O.A." a classic example of film noir. Noir's roots in German Expressionism are evident in several scenes, but perhaps no example is as striking as the scenes within "The Fisherman", the Beatnik nightclub where Bigalow is poisoned.
In the nightclub scene we see the odd closeups and camera angles typical of film noir, but the effect goes beyond film technique. The club patrons are frenzied, they're moving with unnatural responses to wild Jazz music. The musicians are bug-eyed and sweating, but it's more than that; they appear dangerous, possibly possessed. A mysterious figure with a checkered scarf exchanges Bigelow's drink for the poisoned version. We don't see the figure's face, but he is calm, quiet, and as such he stands out against the frenzied crowd. However the crowd is too frenzied to notice.
It isn't clear if the film intended to sound a warning against the threat of nuclear poisoning, but it doesn't take much to justify this argument. Frank Bigelow came into harm's way while performing his simple day to day duties as an accountant and notary. He wanted to have a little fun, but got caught up in the excitement and didn't notice the still, calm hand who brought an end to his life.