A girl from the wrong side of the tracks endures scandal and heartbreak when she falls for a high-society boy.

On a snowy eve, Kitty Foyle, an executive at Delphine Detaille's fashion house, is confronted with a choice that will change the course of her life: to marry Mark Eisen, a young, sincere doctor, or to sail away with Wyn Stafford, with whom she has been in love for years and who has just re-entered her life. As she wrestles with her conscience, Kitty thinks back to her youth in Philadelphia: young Kitty gawks at the society "Main Liners" and dreams of her Prince Charming, disregarding the advice of her father, who warns her against trying to go out of her class. Five years later, Kitty meets her prince in the person of wealthy Wyn Strafford, who is so charmed by the girl that he offers her a job at his fledgling magazine. The two fall in love, but Wyn does not have the courage to break from his life in Philadelphia's Main Line society. After her beloved father's death, Kitty goes to New York, where she begins to date Mark while she still longing for Wyn. Wyn finally comes for Kitty and the two are married, but when he takes her home, his family wants to "remake" her and she rebels. Kitty forces Wyn to make a choice, but he remains a prisoner of his family's money and position and the marriage is annulled. Kitty returns to New York, where she learns in rapid succession that she is pregnant and that Wyn is to marry a Philadelphia socialite. Kitty's plans to rear the child by herself come to an abrupt end when the infant dies in childbirth. Several years later, Kitty returns to Philadelphia to open a branch of the Delphine Detaille fashion house and has a chance encounter with Wyn's wife and son. Finally, as Kitty ponders her past, she decides that there is only one future for her, and she leaves to marry the waiting Mark.