The love which binds mother and daughter - seen through the prism of one mother's life as it crests with optimism, navigates a turning point, and ebbs to its close. Overcome by the power of memory, Ann Lord (Vanessa Redgrave) reveals a long-held secret to her concerned daughters; Constance Haverford (Natasha Richardson), a content wife and mother, and Nina Mars (Toni Collette), a restless single woman. Both are bedside when Ann calls out for the man she loved more than any other. But who is this "Harris", wonder her daughters, and what is he to our mother? While Constance and Nina try to take stock of Ann's life and their own lives, their mother is tended to by a night nurse (Dame Eileen Atkins) as she journeys in her mind back to a summer weekend around fifty years before, when she was Ann Grant (Claire Danes), a young woman who has come from New York City to be maid of honor at the high-society Newport wedding of her dearest friend from college, Lila Wittenborn (Mamie Gummer). The bride-to-be is jittery, and turns to her maid of honor rather than her own mother for support. Ann stays close to her friend, yet is even closer to Lila's irrepressible brother Buddy Wittenborn (Hugh Dancy). Unexpected feelings surge forth once Ann meets wedding guest Harris Arden (Patrick Wilson), a life-long friend and intimate of the Wittenborn family. Ann's love for Harris will change her life, and those of her daughters, forever.