30-year-old hardworking Bobby Grady is married with two children, and his marriage to frigid Amy is in crisis. Bobby is invited to work the night shift at a fashion-design studio whose owner believes that his talented, introspective designed Joanna Crane is selling his designs to competitors. Bobby accepts the job to make money and please Amy with a bathtub. Following Joanna after-hours, he discovers her double life, working as $50-hooker China Blue in the red-light district, satisfying her clients' fantasies with kinky sex. Bobby becomes obsessed with China Blue, and when the true thieves are found, he has sex with her and thinks he's in love with her. Meanwhile, insane preacher Rev. Peter Shayne (Anthony Perkins) decides to save Joanna's soul and stalks her everywhere.