Nick Smith, a middle-aged roadside diner owner, hires a drifter, Frank Chambers, to work at his restaurant. Frank quickly begins an affair with Nick’s beautiful young wife, Cora, and the two conspire to kill Nick and seize his assets. When they succeed, local prosecutor Kyle Sackett becomes suspicious, but is unable to build a solid case. However, the couple soon realizes that no misdeed ever goes truly unpunished.