Cover-Up transfers the metropolitan "film noir" milieu to a small Midwestern town. Dennis O'Keefe plays Sam Donovan, an insurance detective, investigating the suicide of a policy holder. All signs point to murder, but no one in the victim's hometown is willing to cooperate with Donovan, least of all sheriff Larry Beat (William Bendix). Local girl Anita (Barbara Britton) breaks through the wall of silence and helps Donovan solve the mystery. Intriguingly, the action of Cover-Up takes place at Christmastime, with the tinselly Yuletide atmosphere providing stark contrast to the sordid murder story.