Walter Williams (Brian Donlevy), a wealthy San Francisco industrialist, discovers his wife Irene (Helen Walker) is plotting his murder with her lover, Jim Torrence. During a business trip, Irene feigns illness and asks Walter to drive her "cousin" (who is actually Jim) along the way. In the remote Sierra mountains, Jim tries to murder Walter, but a twist of fate results in Jim’s own death. Believing Walter is dead, the police find the body and the case is closed. Walter, having survived but suffering from amnesia and shock, wanders to a small town in Idaho to start over. There, he falls for a kind widow, Marsha Peters (Ella Raines), and eventually plots his revenge.