Wealthy ad man Eddie Anderson makes a suicide attempt in his car. He is contemptuous of life and its “arrangements.” His long marriage to Florence is now devoid of passion, and he has become the lover of Gwen, a research assistant at his Los Angeles advertising agency. He descends into a long depression and silence, often conjuring up memories or hallucinations of Gwen.
A psychiatrist, Dr. Leibman, eventually listens to stories of Eddie’s nightmares and general discontent with life. Eddie returns to work, where he insults a valued client. He pilots a small plane about L.A. and buzzes its skyscrapers recklessly, causing the police to be called. His mental stability is now seriously in doubt. His wife also sees compromising photographs of Eddie and Gwen.
Arthur, his lawyer, gives wife Florence power of attorney as Eddie travels to New York to visit Sam Arness, his ill father. The father is so sick that Eddie’s brother and sister-in-law want him placed in an institution. Gwen is also in New York now, living with a man named Charles and telling Eddie of many other affairs that she has had. She has a baby that she claims is not Eddie’s (but it is strongly implied she’s lying).
A delusional Eddie begins to have conversations with his alter ego. Arthur brings papers for him to sign, turning over all of his community property to Florence, but she tells him not to sign them, and it turns out he signed someone else’s name. Florence and Eddie have a long intense conversation, in which Eddie says he just wants to do nothing for a while—Florence simply can’t understand this, and says he’s insane. He sets fire to his father’s house and comes to Gwen’s apartment, where Charles shoots him—after this, Eddie is committed to a psychiatric hospital, but can release himself at any time, simply by proving he’s got a job and a home to go to.
Eddie seems to feel contentment in his solitude at the asylum, but Gwen brings the baby to see him, and manages to lure him outside to try again, saying she’s got a job for him. At his father’s funeral, Florence and Gwen are both there and see each other for the first time, and Florence seems to grudgingly accept the relationship between Eddie and Gwen as the only way Eddie can be saved from himself.