The title of this French noir drama translates to The Black File. Jean-Marc Bory plays Jacques Arnaud, an idealistic young investigator who comes to work in a small French town. He is soon involved in a mysterious case incriminating a town notable. Arnaud devotes himself to the case but the upshot of this is rather surprising to all concerned, not to mention the audience. Like Cayatte's previous efforts, Le Dossier Noir is based on the proposition that the phrase "French justice" can at times be oxymoronic.
~ Hal Erickson, All Movie Guide