Kate Croy's mother was born to wealth and privilege, but she threw it all away to marry Kate's father, a penniless opium addict who admits to having stolen from his wife. After her mother's death, Kate is offered an opportunity to return to the life her mother gave up. There is a condition, however: Kate must sever all of her old ties, not only to her father, but also to her lover, the muck-raking journalist Merton Densher, whom she has promised marriage. Kate reluctantly agrees to this, and in the meantime becomes friendly with 'the world's richest orphan,' Millie Theale, an American making the Grand Tour. Desperate to see Kate, Merton crashes a party that she and Millie are attending, and Millie is attracted to him. When Kate learns that Millie is dying, she comes up with a plan to have her cake and eat it too...but all does not go as planned.