Ordinary People is a novel which tells the story of the Jarrett family, who are having a difficult time coping with the death of their oldest son Buck the year before. Their other son, Conrad, is severely depressed and having trouble relating to his parents. When both Conrad and his father Calvin begin seeing a psychiatrist, they are able to resolve their issues with themselves and with each other. Conrad's mother Beth is ultimately unable to do the same, and leaves the family.
The novel begins as life is seemingly returning to normal for the Jarretts of Lake Forest, Illinois, in September 1975. It is slightly more than a year since their elder son "Buck" was killed when a sudden storm came up while he and their other son Conrad were sailing on Lake Michigan. Six months later, a severely depressed Conrad attempted suicide by slashing his wrists with a razor in the bathroom. His parents committed him to a psychiatric hospital from which he has only recently returned after four months of treatment. He is attending school and trying to resume his life, but knows he still has unresolved issues, particularly with his mother, Beth, who has never really recovered from Buck's death and keeps an almost maniacally perfect household and family.
His father Calvin, a successful tax attorney, gently leans on him to make appointments to see a local psychiatrist, Dr. Tyrone Berger. Initially resistant, he slowly starts to respond to Dr. Berger and comes to terms with the root cause of his depression, his identity crisis and survivor's guilt over having survived when Buck did not. Also helping is a relationship with a new girlfriend, Jeannine Pratt.
Calvin sees Dr. Berger as the events of the recent past have caused him to begin to doubt many things he once took for granted, leading to a midlife crisis. This leads to strain in his marriage as he finds Beth increasingly cold and distant, while she in turn believes he is overly concerned about Conrad to the point of being manipulated. Finally the friction becomes enough that Beth decides to leave him at the novel's climax. Father and son, however, have closed the gap between them.