In an underground tesseract shelter originally built for the unhoused in Los Angeles, Mull, a middle aged environmental analyst and former professor, meets a man who claims to have fallen through a window into the desert. Mull isn’t sure he believes the man because the four dimensional house they live in seems impossible to leave. Its rooms and hallways are constantly shifting, which makes it difficult for Mull to find the woman he is looking for: Rose Gutiérrez.  The tesseract house was conceived of by an architect named Quintus Burnham as a solution for the unsheltered in Skid Row. Burnham built the house using hyper cubic spatiality. Then, a series of earthquakes struck the area and the tower collapsed and sunk into the ground. All of the inhabitants were trapped in the house. Some people speculate that the tower’s construction might have caused the earthquakes by disrupting a fault line.  At a press conference about the collapse, a young man shoots Quintus Burnham but doesn’t kill him. The would-be assassin, James Gutiérrez, is one of Mull’s former students. Mull visits James in jail where James explains that he shot at Burnham because the tesseract house swallowed his mother, Rose. He’s angry about the policy of urban removal. He asks Mull to find his mother and tell her what he did. Mull goes to the atrium, where there’s a seemingly inexhaustible supply of food, to search for Rose. He runs into the man who speaks of the desert window again. The man claims to have seen Mull before they both entered the tesseract house. The man takes Mull to see the window, which looks out on the desert east of Los Angeles. The man insists that he went through the window and then hitchhiked his way back to the house, but Mull doubts his story. It’s a far drop from the window. Also, Mull has tried to escape the house before and it seems impossible. Because the house adapts to each occupant, it’s difficult for Mull to wander to new rooms in search of Rose. The house keeps trying to redirect him. He decides to follow other occupants and finds a gymnasium with a pool. There are mostly women in the pool and they tell him he doesn’t belong there. Then Mull follows a younger man, who turns out to be trailing an older man through the house. The three of them enter the jail where Mull visited James Gutiérrez. The house and the jail have somehow melded together. Mull realizes that the older man being trailed by the younger man being trailed by Mull is actually himself. Several inhabitants of the house capture him and put him in a jail cell. It dawns on him that they’ve been living in a prison all along. When Mull insists that he needs to find Rose, his captors inform him that her son James is taking care of her.  His captors then push him out of the desert window and he lands in the sand. There’s a roadway nearby that he hadn’t noticed before. Mull intends to follow the road west and make his way back to the house.