The novel begins at a speakeasy in Harlem on New Year's Eve, where protagonist Max Disher's romantic advances are rejected by a white woman solely because he is Black. The following morning, he reads about a new scientific procedure for turning Black skin white called "Black-No-More," and he decides to go through with the procedure, being the first to do so. As Max sees his face broadcast on the news for undergoing the procedure, he expresses concern, until remembering that he is now unrecognizable due to now being white.
As the Black-No-More procedure grows increasingly popular, it wreaks havoc on the social and economic institutions of Harlem, drawing resistance from leaders in the African American community. It also draws fierce resistance from Southern segregationist organizations, as the Southern economy rooted in Black labor collapses. Meanwhile, Max — who has now changed his name to Matthew Fisher — discovers that life as a white man is not as great as he imagined, with economic struggles remaining a constant in his life. In order to earn some money, he travels to Atlanta, Georgia, and joins Reverend Harry Givens's white supremacist organization, The Knights of Nordica, claiming that he has the expertise necessary to help them end Black-No-More.
Incidentally, the woman who rejected Matthew at the beginning of the novel is Rev. Givens's daughter, Helen. Now that he is white and a prominent member of a white supremacist organization, Matthew wins Helen's affection and, eventually, her hand in marriage. This becomes dangerous for Matthew, however, when Helen becomes pregnant, raising the specter — faced by an increasing number of newly whitened individuals — of a non-white child betraying his true identity.
The Knights of Nordica break into politics, teaming up with the well-funded Anglo-Saxon Association, whose leader, Arthur Snobbcraft, shares the Democratic presidential ticket with Rev. Givens. With fewer and fewer Black individuals left for Snobbcraft and Givens to stake their racist positions against, they hire a statistician, Dr. Samuel Buggerie, to conduct a massive inquiry into the genealogy of American citizens and thereby taint their opponents as genealogically, if not epidermically, "Black."
After a miscarriage, Helen becomes pregnant again, prompting Matthew to keep an airplane and spare cash on hand for a quick escape whenever she happens to go into labor. He decides that, when she gives birth to what will inevitably be their Black child, he will ask her either to reject him outright, or to accept him for who he is and leave the country with him. However, with the genealogy project nearing completion on the eve of election day, the results indicate that almost all Americans have at least some African ancestry, including Snobbcraft, Buggerie, Givens, and Helen. These results are stolen by the Republicans and then leaked to the media. When Helen's child is born biracial, she blames herself for her undisclosed African-American heritage. Matthew then admits his own heritage, and she accepts him for who he is.
A violent mob forms when word spreads of Givens's and Snobbcraft's "impure" ancestry. Snobbcraft and Buggerie flee together on Matthew's airplane, but they are forced to land in Mississippi when they run out of fuel. Afraid of revealing their true identities, they blacken their faces with shoe-polish, which proves to be an unfortunate decision, as they encounter a group of local zealots who have been eagerly waiting for a Black person — any Black person — to kill. Givens and Snobbcraft remove their disguises and convince the zealots that they are, in fact, white, but just at this moment a newspaper arrives, divulging their true ancestry. Snobbcraft and Buggerie are mutilated and then burned alive.
In a flash-forward, Dr. Crookman, the creator of the Black-No-More procedure, announces that Black Americans who undergo the procedure appear lighter, which results in those with light skin facing discrimination, and having a darker skin tone becoming increasingly desired. As a result, both Black and white Americans begin staining their skin with the product "Zulu Tan" to appear darker. The novel closes on a picture of Max and Helen's family, in which all are dark-skinned.[4]
