In a dilapidated Los Angeles ghetto, young Poindexter "Fool" Williams discovers that his family faces eviction from their tenement apartment. Desperate to find money to keep the roof over his sick mother's head, Fool is drawn into a scheme by Leroy, his sister's boyfriend, to burglarize the home of the wealthy and reclusive landlords of the ghetto, the Robesons. The Robesons are known in the neighborhood for being eccentric and antisocial, but they are rumored to keep a collection of rare coins in their house. Fool, though apprehensive, agrees to join the heist, seeing it as the only way out of his family's dire situation.

The burglary quickly goes awry as Fool and Leroy discover that the Robeson house is a fortified labyrinth with secrets more twisted than they could have imagined. The dwelling is rife with hidden passages, traps, and horrors that supersede mere physical fortifications. After his accomplices are taken out of commission, Fool finds himself trapped inside, facing not only the sadistic Robesons but also the chilling truth about the children who have fallen victim to the couple's depravities. As Fool struggles to escape, he encounters a girl named Alice who has been raised by the Robesons, and together they uncover the monstrous nature of their captors’ desires and the gruesome reality of who, or what, dwells beneath the stairs.