An intern is tested in diagnostics by a dying expert and helps a young woman, who tried to commit suicide.
Alice Raymond (Lynne Carver) hopes her boy-friend will practice medicine with his father Dr. Stephen Kildare (Samuel S. Hinds). Dr. James Kildare (Lew Ayres) arrives on a train and is welcomed by them and his mother Martha Kildare (Emma Dunn). Jimmy goes swimming with Alice, who realizes he doesn't want to stay there. Jimmy tells his father he took a job in New York, and his mother wishes him well.
Intern Kildare reports to Dr. Carew (Walter Kingsford) and meets Dr. Leonard Gillespie (Lionel Barrymore). Kildare volunteers to examine Gillespie's hands. Gillespie summons Kildare and mocks him. He has Kildare diagnose several children and corrects a mistake. Kildare says Gillespie has cancer and with luck one year. Ambulance man Joe Wayman (Nat Pendleton) asks a nurse for a date. Kildare tells Joe to give a drunk oxygen and goes to save a woman (Jo Ann Sayers) from suicide. He works to get her breathing, and she revives. Gillespie asks Kildare about her. The drunk politician died, and Kildare is taken off ambulance. Joe thanks Kildare for not blaming him and warns him the girl tried suicide again. Kildare promises her not to tell her secret, and she decides to live. Kildare learns she is Barbara Chanler and meets her wealthy parents and her fiancé Jack Hamilton (Truman Bradley). Psychiatrist Lane-Porteus (Monty Woolley) says she is schizophrenic, but Kildare disagrees and refuses to reveal her confidences. Dr. Lane-Porteus sends her mother in over Kildare's objection, and Barbara gets upset. Dr. Carew orders Kildare to tell, but he refuses and is suspended.
Alice finds Kildare getting a beer. He says he may come home, but he wants to be a diagnostician. Kildare assures his parents he did not cause the politician's death, and his mother encourages his self-confidence. Kildare learns about the Blue Swan from Barbara's fiancé Jack and finds Bert Foster. Kildare tells Gillespie he knows why Barbara tried suicide and gets in to see her. Kildare tells Barbara what Foster did while she was drunk to relieve her fear. He tells her to explain without mentioning him. Kildare is discharged by the hospital board. Kildare sees Barbara embraced by Jack and tells his parents he is coming home. Dr. Gillespie tells Kildare that Barbara's parents are so happy that they have given Dr. Carew a fat check, and he makes the young intern his assistant.
This first medical drama about Kildare is poignant with the outstanding acting of Lionel Barrymore, recently crippled by arthritis in a wheelchair. Dr. Gillespie's frankness cuts to the core, and the integrity and skill of young Kildare reflects his fine upbringing.