Kate, the protagonist of the movie The Wings of the Dove, is an attractive and charming young woman who meets Merton Densher, a struggling journalist. The two of them fall in love, but their social and financial backgrounds make their future together uncertain. Kate's Aunt Maude, who is her legal guardian, disapproves of their relationship, and Kate knows that any hopes of marrying Merton will be crushed if her aunt finds out.
Kate's mother had made a disastrous marriage to an opium addict, which had left her penniless and with no family support. As a result, Aunt Maude has taken on the responsibility of Kate's upbringing. She is a severe and controlling woman who is determined to keep her niece well away from any men who might be unsuitable for her.
Despite Kate's fears, Merton confesses his love for her and proposes marriage. Kate knows she cannot accept without her aunt's approval, so she concocts a scheme to manipulate a wealthy American heiress, Millie, who is traveling in Europe. Kate befriends Millie and learns that she is dying of a terminal illness. Kate concocts a plan to persuade Millie to leave her fortune to Merton, on the condition that he agrees to marry Millie.
Initially, Merton is appalled at Kate's suggestion, but eventually, he is persuaded that it is the only hope for their future together. As he enters into the arrangement with Millie, he becomes more and more distant from Kate. Kate, who had assumed that her plan would bring happiness to everyone, begins to feel guilty and powerless as she watches Merton become increasingly distanced from her.
The movie shifts between romantic love, tragic death, and unrequited love throughout, ending with a shocking twist that explores the depths of human desire, deceit, and vindictiveness.