Octavia Butler's novel sends Dana, a Black woman living in 1970s Los Angeles, repeatedly back in time to antebellum Maryland, where she must protect Rufus, a white slaveowner's son whose survival ensures her own existence. Dana discovers that Rufus is her ancestor; if he dies before fathering children with Alice, an enslaved woman, Dana's family line--and Dana herself--will cease to exist. The novel uses time travel not as science fiction gadgetry but as a device to collapse the distance between contemporary Black Americans and the slavery that shaped their history. Butler examines how slavery corrupted everyone it touched: Rufus, who might have been decent in other circumstances, becomes cruel; Alice, who has no good choices, is destroyed; even Dana, trying merely to survive and return home, compromises in ways that haunt her. Butler wrote the novel in part to counter what she saw as romanticization of slavery in popular culture, forcing readers into visceral encounter with the institution's violence and degradation. The book became a foundational text in what critics now call 'neo-slave narratives,' fiction that revisits slavery's trauma to understand its continuing effects. Butler demonstrates how genre fiction can address history as seriously as any literary novel, reaching audiences unfamiliar with academic historiography.