Tommy Wilhelm, who changed his name from Wilhelm Adler as a young man and aspiring actor, is a stressed-out, middle-aged man weary of fulfilling social expectations of financial success. He has a talent for making poor decisions, often selecting a choice he has determined to be wrong. He left college against his parents' and casting agent's advice, determined to become a Hollywood actor. When that failed he became a salesman, married, and had two children. He becomes estranged from his wife, who refuses to divorce him and allow him to marry his mistress. When a younger man is given half of his sales territory, Wilhelm quits his job. The pressure of providing for his wife and children on no income, as well as pay his rent at a residential hotel, leaves Wilhelm in a panic. He falls under the influence of a conman, Dr. Tamkin, and invests his remaining savings in the commodities market after his father refuses to help him. Rejected by his father and duped out of his money, Wilhelm finds release for his emotions at the funeral of a stranger.
Dr. Adler is a retired, successful doctor who wants to live out his remaining years in peace. Although he enjoys the prestige his children's past successes lent him, he has grown ashamed of them and resents their requests for financial help. He sees no reason for their problems being forced on him. He is a proud and critical man. His son's failures and slovenliness irritate him, and he has no sympathy for him. When his son repeatedly asks for help, Dr. Adler becomes furious and tells his son he would rather his son die than pull him down.
Dr. Tamkin is a man with dubious credentials: a psychologist, inventor, and investment expert. He enjoys telling stories about his many patients, all of whom have exotic or titillating disorders. He is an odd-looking older man who seems to know everyone in his community. He makes big promises to Tommy Wilhelm about the capacity of commodities trading to make easy money, successfully persuading Wilhelm to partner with him in a large investment. Dr. Tamkin urges Wilhelm to focus on the present and make the most of the opportunities he has in front of him rather than thinking of the past or fearing the future. When their investments lose value, Dr. Tamkin disappears.
Margaret Wilhelm is the estranged wife of Tommy Wilhelm. She is demanding and unrelenting. She believes she is entitled to her husband's financial support, and she controls him by refusing to grant him a divorce, which would allow him to remarry. Although she has a college education, she refuses to seek employment, using her children's care as an excuse. She has no pity for her husband's financial or personal struggles, and she can't bear any display of his emotions.