“Atlantis: Model 1924” belongs among the most important fiction in Samuel R. Delany’s vast bibliography, precisely because it distills so much of what makes this black, gay Harlemite science fiction writer such a unique figure in American letters—including his family’s history, his thinking on race, sexuality, and gender, his artistic methods as a writer, and his creative approach to literary criticism. “Atlantis: Model 1924” follows the life of a 17-year-old black kid named Sam on his journey from North Carolina to Harlem in the fall of 1923. The character is based on the author’s father, and the storyline is based on Delany’s family history. Two of the fictional Sam’s siblings — Elsie and Corey in the novella — are based upon the famous Delany sisters, Sarah (Sadie) Delany and A. Elizabeth (Bessie) Delany, who became internationally known centenarians with their bestselling book Having Our Say: The Delany Sisters’ First 100 Years (1993).