The story is written as a third person narrative from the perspective of Irene Redfield, a black woman with a European or near-European appearance, who lives in the Harlem neighborhood of New York City.
Part One of the book, titled "Encounter," opens with Irene receiving a letter from Clare Kendry, causing her to recall a chance encounter she had had with her, at the roof restaurant of the Drayton Hotel in Chicago, during a brief stay in the city. Irene does not answer Clare's letters attempting to reconnect. The women grew up together but lost touch when Clare's biracial father died and she was taken to live with her two paternal white aunts. Irene learns that the beautiful Clare, who appears European, passes for white, living primarily in Europe with her unsuspecting, rich, racist white husband and their daughter. Although Irene tries to avoid further engagement with Clare, she never is able to fully exclude her from her life as she later visits Clare for tea along with another childhood friend, Gertrude Martin. Toward the end of the visit, Clare's white husband John (Jack) Bellew arrives. Unaware that all three women have black ancestry, Jack enthusiastically affirms his hatred of black people, making the women uneasy. In a startling passage, he also reveals his pet name for Clare, "Nig". Although Jack does not suspect that his wife has black ancestry (and, in fact, believes that his "Nig" hates black people as much as he does), he gave her that name because he perceives that Clare, who was "white as a lily" when they were married, has been "gettin' darker and darker". Irene and Gertrude say nothing in response, in part to maintain Clare's secret identity. Afterwards, Irene receives a letter of apology from Clare but destroys it in an effort to forget about Clare and excise her from Irene's life. Irene seeks instead to focus on her own life with her husband, Brian, and her two sons, Theodore and Junior.
Part Two of the book, "Re-encounter," returns to the present, with Irene having received the new letter from Clare. After Irene ignores Clare's letter, Clare visits in person, and Irene reluctantly agrees to see her. When it is brought up that Irene serves on the committee for the "Negro Welfare League" (NWL)[b] Clare invites herself to their upcoming dance despite Irene's advice against it, for fear that Jack will find out. Clare attends the dance and enjoys herself without her husband's finding out, which encourages her to continue spending time in Harlem. Irene and Clare resume their childhood companionship, and Clare frequently visits Irene's home.
The third and final part of the novel begins before Christmas, as Irene's relationship with her husband has become increasingly fraught. Aware of her friend's attractiveness, Irene becomes convinced that her husband is having an affair with Clare. During a shopping trip with her visibly black friend, Felise Freeland, Irene encounters Clare's white husband, Jack, by chance. Although Jack recognizes Irene and attempts to greet her, Irene pretends not to know him. Nevertheless, as Irene fully understands, this chance meeting carries the potential to expose Clare's secret. Irene considers warning Clare about Jack's newfound knowledge but decides against it, worried in part that the pair's divorce might encourage her husband to leave her for Clare. Later, Clare accompanies Irene and Brian to a party hosted by Felise. The gathering is interrupted by Jack, who accuses Clare of being a "damned dirty nigger!" Irene rushes to Clare, who is standing by an open window. Suddenly, Clare falls out of the window from the top floor of the building to the ground below, where she is pronounced dead by the guests who eventually gather at the site. Whether she has fallen accidentally, was pushed by either Irene or Bellew, or committed suicide, is unclear. The book ends with Irene's fragmented anguish at Clare's death.
