At Blair General Hospital in New York City, Dr. Tommy Coalt, an accomplished surgeon with a brusque bedside manner, is temporarily reassigned to a doctor's office in the small town of Bayhurst by head surgeon Dr. Leonard Gillespie. Tommy is asked to take over Dr. Sanford Burson's private practice for six weeks while Burson is out of town. En route to Bayhurst, Tommy gets lost and stops to ask a young woman for directions. He notices that the woman is behaving in a strange manner, but when he asks her about her problem, she runs away. Tommy's first house call in Bayhurst is to Wyndham Grace, the town's wealthiest and most prominent citizen, who wants Tommy to put his signature on a document that will authorize the commitment of his daughter Cynthia to an insane asylum. Tommy immediately recognizes Cynthia as the woman he met by the road, and flatly rejects Wyndham's assertion that she is a schizophrenic. Dr. Evans Biddle, the only other doctor in Bayhurst, has signed the asylum admission papers, but Tommy is certain that Cynthia is not seriously ill. After leaving the Graces, Tommy visits the Selkirks, a young couple in the process of adopting a baby boy. Tommy tells Mrs. Selkirk that her husband Teddy must stop avoiding the physical examination required by law before they can finalize the adoption of their baby. While at the Selkirks', Tommy receives an urgent telephone call from Walters, the Grace family chauffeur, who has found Cynthia behaving oddly at a department store. Tommy races to the store, and arrives in time to witness Cynthia shoplifting merchandise. When Tommy asks Cynthia what she has just done, her thoughts become clouded, and she is slow to realize what has happened. Tommy tells Cynthia that she suffers from kleptomania, but insists that he must perform more studies to determine the cause of her behavior. Later, after accidentally starting a fire at her birthday party, Cynthia flees from her father's house, and takes refuge in Tommy's office. The following day, Wyndham telephones Dr. Gillespie to tell him about his daughter's disappearance. Later, when Teddy presents Tommy with a medical examination report, Tommy realizes that the report is a fake and demands that Teddy submit to a real examination. Dr. Gillespie then makes an unannounced visit to Bayhurst and tells Tommy that he may be facing a number of criminal charges, including kidnapping and malpractice. After convincing Dr. Gillespie that Cynthia does not require institutionalization, Tommy tries to diagnose her problem using "narcosynthesis," a procedure involving truth serum. During the procedure, Cynthia tells Tommy that she did not see a doctor after a fall from a horse months earlier. Tommy takes Cynthia to Brookline Hospital, where he soon discovers a blood clot in her brain. Meanwhile, in Bayhurst, Dr. Lee, a Chinese-American doctor from New York, takes over for Tommy during his absence and learns that Teddy has been hiding a heart condition from doctors. However, an impromptu physical examination shows that Teddy's concerns are unfounded and that he is healthy enough to adopt. Weeks pass, and Tommy returns to Bayhurst with Cynthia, who has fully recovered from her brain surgery. When Dr. Burson returns, he asks Tommy to stay in Bayhurst and hires him to help him in his practice.