Dave Garver is a popular radio disc jockey who repeatedly receives on-air phone requests from a mysterious female fan to "play Misty for me". When the woman, Evelyn Draper, actually appears at his favorite bar one night, the two begin an impassioned romance. But soon Evelyn reveals herself as an obsessive woman with symptoms of mental disorder and ties Dave up, he decides to quit the relationship. Upon his decision, Evelyn's obsession turns to deadly violence and she now vows to destroy everyone and everything in his life.