Small town scandals inspire an idealistic young man to take up psychiatry.

Growing up together in the late nineteenth century in the small town of Kings Row are Parris Mitchell, who lives with his French grandmother; Cassandra Tower, the misunderstood daughter of Dr. Alexander Tower; wealthy orphan Drake McHugh; Louise Gordon, the daughter of sadistic Dr. Henry Gordon, who performs operations without anesthetic; and Randy Monaghan, whose father is a railroad worker. Although the other children in town avoid Cassie, whose mother is rumored to be locked in an upstairs room of the Tower residence, Parris is attracted to her and is her only friend. Eventually Tower decides to keep Cassie at home and Parris does not see her again. Several years later, in 1890, Parris begins his medical studies under Dr. Tower's tutelage. His best friend, Drake, intends to marry Louise despite the disapproval of her rigidly moralistic father. Louise, however, does not have the strength to defy her parents. One day, when Parris returns to the Towers' to retrieve his notebooks, Cassie meets him. She refuses to explain why she can never see her friends, and intrigued by her wildness, Parris kisses her. It is late when Parris leaves, and to save Cassie's reputation, he spends the night with Drake. Subsequently, Parris and Cassie continue to see one another at Drake's. Meanwhile, Parris' grandmother has become very ill. Although Parris is concerned about Gordon's seeming mistreatment of his patients, Tower assures him that the doctor's abilities are adequate to treat his grandmother, and a short time later she dies from incurable cancer. Parris becomes interested in psychiatry and decides to continue his studies abroad. He proposes marriage to Cassie, who runs from the room in distress. Later she visits him at Drake's and begs him to take her with him, but again, runs away. The next day, Parris learns that Tower has poisoned Cassie and shot himself, leaving everything to him. Tower's notebook reveals that he killed Cassie, who was insane like her mother, to prevent Parris from ruining his life by marrying her. By 1900, Parris is in Vienna studying psychiatry, while in Kings Row, Drake's plans to build houses are encouraged by his new sweetheart, Randy Monaghan. Randy suggests that he build homes for workers rather than the rich, but when his trust fund is stolen by a dishonest bank officer, Drake is forced to work for the railroad. He is accidentally crushed by a boxcar and Gordon is called to treat him. Gordon's hatred of Drake prompts him to amputate his legs needlessly. Parris, meanwhile, has learned of the events and, after Randy and Drake marry, offers them money to start over. Later, Parris takes a leave of absence from his studies to visit Kings Row and decides to remain there when he learns that because of Gordon's death, the town needs a doctor. At Mrs. Gordon's request, he visits Louise, who has not left her room since Drake's marriage. Louise reveals that her father amputated Drake's legs because he believed it was his duty to punish wickedness. This is confirmed by Elise Sandor and her father, who now live in Parris' old house. At first, Parris wants to keep the truth from Drake, but instead, persuaded by Elise, confronts him with the facts. Unexpectedly, Drake is relieved, and is finally able to accept his life. Having cured his friend, Parris is now free to marry Elise.