Out of the Past (1947)

An archetypal film noir with all the ingredients in place: the tough but easily led hero played by Robert Mitchum with his usual sleepy efficiency, the quintissential femme fatale in Jane Greer, the suave but slimy Mr. Big played here by Kirk Douglas in a supporting role (one forgets that Mitchum was the bigger star then) and brilliant shadowy black and white composition.  Perhaps the plot is over-complicated but one just knows that there can never be the hoped-for happy ending.