One afternoon, in the San Fernando Valley, Dennis Williams drives to the house of his lover, Jane Bandle, who becomes concerned about his presence as her husband Fred is due home shortly. Although Dennis tells Jane that Fred has found out about their affair, probably through a private investigator, Jane is happy that their six-week relationship is now out in the open. However, Dennis, sure that others will make it all look sordid, worries about the effect the affair will have on his two teenage daughters, whom, he feels, must come first. He is anxious to maintain his scandal-free reputation and, therefore, tells Jane that their affair is over and that he is returning to his wife Katherine. Jane, who had wanted out of her loveless marriage, is totally disillusioned by Dennis' rejection and threatens to commit suicide with a shish kebab skewer. Dennis tries to stop her, but accidentally falls on the skewer, stumbles into the laundry room and collapses. Jane panics and realizes that she must somehow conceal Dennis' lifeless body, but procrastinates and is interrupted by two Girl Scouts collecting clothes for refugees in Europe. Then, her rough-edged brother-in-law Bill stops by looking for Fred and decides to wait for his return. Jane is distant with Bill when he talks about the old days and how she caused a rift between Fred and him: At a picnic, when an eighteen-year-old Bill gets drunk and tries to kiss Jane, and she tells Fred to "keep that filthy kid" away from her. In the present, Bill grabs Jane and kisses her. She slaps him and threatens to tell Fred, but Bill then reveals that Katherine Williams is coming over with her husband Dennis, to meet Fred. Jane learns that it was Bill who hired the detective and has set her up out of revenge. When Katherine arrives from Beverly Hills, she notices that Jane is trembling. After Bill prevents her from phoning the police, Jane slips out of the house and attempts to catch a bus, but Fred, who is driving home, spots her and picks her up. Back at the house Bill introduces Katherine to Fred, who assumes she is Bill's date. Bill then takes Fred outside to tell him about Jane's affair while Katherine tells Jane that, as the wronged wife, she is supposed to hate her, but does not, considering her merely a fool and a weakling. After Katherine informs her that Dennis had two other affairs, Fred returns and asks if she has anything to say. When she does not respond, he slaps her, then demands to know when Dennis is going to arrive. Jane breaks down and takes them to where she left his body, but it is gone. Jane becomes hysterical as Fred and Katherine follow a trail of blood and Bill phones for an ambulance. When questioned, the two Girl Scouts tell Fred and Katherine that they saw an ice cream truck stop and drive Dennis to a hospital in Van Nuys. Katherine phones the hospital and learns that Dennis is recovering, that he still loves her and that his lung injury has been designated as an accident. Jane goes into her bathroom and cuts her wrists, but the ambulance Bill summoned arrives and the two attendants treat her. Before Katherine accompanies Jane to the hospital, Bill tells the ambulance men to report the injury as an accident. While Fred packs items to take to Jane in the hospital, Bill tries to persuade him to abandon her, revealing the depth of his jealousy. Fred, however, accuses Bill of setting it all up, and claims that he has always been jealous of him and his life with Jane. When Fred goes to his car, Bill follows and declares that Jane is a double-crossing cheat, whereupon Fred punches him on the jaw and tells him to keep away from them. Fred then drives off while Bill runs hysterically after the car.