Dr. Michael Corday, only son of prominent New York neurosurgeon Dr. John Corday, has just graduated from medical school. His family welcome him home with open arms. Besides his widowed father, Mike has two sisters, Mariette and Fabienne. Mariette is engaged to George Esmond, a pediatrician. Fabienne rejects the young intern her father invites to dinner and later announces that she is moving into a Greenwich Village apartment. This does not please her father.
Mike can't wait to go into practice with his father but first he must serve a residency at the local charity hospital. His arrogance and name-dropping doesn't go over well with the staff and patients. His supervisor, Dr. Norton, could care less that Mike is the son of a well-known doctor. He forces Mike to break the news to a couple that their daughter has died. Then Mike meets a young woman who has come to the free clinic for treatment. Her name is Evelyn Heldon but everyone calls her Taffy because she operates a taffy machine in a store. When Mike tells her to remember that he is a doctor, she tells him to remember that she is a patient. Taffy has a serious lung condition that will require surgery. Mike is drawn to her and asks a family friend, Dr. Garard, to perform the operation. He feels Taffy will have a much better chance of survival.
The Corday family gather once a week for dinner. Mike is starting to realize how controlling his father is when the elder man chooses the wedding date for George and Mariette. Since Fabienne has moved out, Mariette has decided that she and George will live with her father. She doesn't want to leave him alone with just the housekeeper. Mike protests this and tells Mariette she has every right to a home of her own. His father is sure Fabienne will come home once Mariette is married, but Mike knows she has no intention of doing so.
The time comes for Taffy's surgery, which is successful. Word has spread in the hospital that she and Mike are "an item" and she receives special treatment from the nurses. Mike hasn't told his family about her, knowing his father will disapprove because she is poor and lacks social standing. But Dr. Corday Sr. has already heard about her. He asks Dr. Garard to release her from the hospital, with a warning to stay away from Mike.
Mike is furious when he discovers Taffy is gone. He confronts his father, who reminds him that at this point in his career he must focus on medicine and not on romance. That would be true even if Taffy was the most suitable girl in the world. Mike realizes he must make a decision. If he marries Taffy, his father will cut him off.
He walks for hours and finally goes to Taffy's apartment. It is bare and there is almost no food. She hands him letters she has written to him but not mailed because she promised not to. Over her protests Mike decides they will get married as soon as she is stronger. He will open an office right there in the building.
Mike's sisters are fine with the idea but Dr. Corday announces that he has no further plans for his son. This means that the neurological residency will go to someone else and Mike will be nothing more than a general practitioner.
Mike soon has more patients than he can handle. Taffy serves as his office assistant. They see Mariette, George, and Fabienne occasionally but not Dr. Corday Sr. Then Mike discovers that Fabienne is dating a married man. He goes to see his father to ask him to intervene, but Dr Corday coldly refuses. Then Mike answers a call late one night from an overcrowded tenement. The child he goes to see has diphtheria and is rapidly failing. Recognizing that a tracheotomy must be performed but lacking the skill to do it, he sends for George. The child survives but Dr. Corday Sr., when he hears about the incident, wonders if Mike will ever admit his mistake and come home. Mariette replies that Mike was not the one who made the mistake.
Fabienne finds herself pregnant and alone, as her lover has gone back to his wife. Dr. Garard urges her to go home and let Mariette take care of her. But she cannot face her family. Dr. Garard asks how she can face the world if she can't face her own family. Fabienne thanks him and leaves. Later that day, she goes to her father's home when no one is about and locks the door of his study. From the bookshelf, she takes a volume entitled "Pregnancy."
Some hours later, Fabienne is in terrible pain but she manages to dress and go to Mike and Taffy's apartment. Mike carries her to the examining table and orders Taffy to get a blanket. When she returns, Fabienne has obviously told Mike that she tried to abort her baby. He asks her why she hadn't come to him at once and orders Taffy to prepare a dose of morphine. The pain goes away but Fabienne is hemorrhaging and going into shock. She is rushed to the hospital and the family notified. They wait in Dr. Corday Sr.'s office while Dr. Garard tries to save Fabienne's life, but she dies on the operating table. George, who attended the operation, said it was hopeless from the start.
While the family is waiting, they are joined by Taffy. For the first time she meets her father-in-law and he realizes what a mistake he has made. Later, after Fabienne's funeral, he asks Mike and Taffy to come and live with him. Mike can take up the neurological residency and make something of himself. Although Taffy agrees to do whatever Mike wants, it is obvious she is angry. She brings him some patient files and he begins to decide what doctors he will transfer them to. Then a boy with a severe cut on his arm is brought in. Dr. Corday Sr. immediately takes over and starts suturing the cut. The parents ask him what he is butting in for. He laughs and says they are right, that Dr. Mike Corday should be the one to do the suturing. Mike realizes he is no longer interested in working with his father, that his place is here.