At his 1875 engagement party, Newland Archer (John Boles) is surprised to meet his childhood friend Ellen (Irene Dunne), now Countess Olenska; she's the cousin of his fiancee May (Julie Haydon). The strait-laced society of the time regards her as somewhat scandalous, but she's treated well by Newland and his family, so it's he whom she consults regarding a divorce. Although he talks her out of it at first, he reconsiders when he sees she's being pursued by philanderer Julius Beaufort (Lionel Atwill), but Ellen now realizes divorce would upset her family, especially her beloved grandmother (Helen Westley). Newland himself is strongly attracted to Ellen, and considers breaking his engagement to May, but he hasn't reckoned with the powerful rules of his society. The story is told by Newland to his grandson in flashback.