Lydia Hadley is worried about the nursery in the home she shares with her husband, George, and their two children, Peter and Wendy. A realistic simulation of an African veldt or open grassland complete with wild animals, the nursery has recently turned disturbingly hyper-real. The Hadleys live in an expensive HappyLife Home, a fully automated dwelling designed to entertain them and cater to their every need. George steps into the enormous nursery with Lydia to examine her concerns. He feels the sun’s heat on his face as if it were real. The lions on the crystal screens of the walls have just finished hunting something and are on their way to the watering hole. The couple can smell the lions, the dust, and the grass in the sun. George is disconcerted by how lifelike it all appears, but he also marvels at the “mechanical genius who conceived this room.” Just then, the lions seem to rush towards Lydia and George. Lydia screams and the couple run out. George downplays the incident as an overreaction by Lydia, but he agrees to locking the nursery for a few days so Wendy and Peter cannot play there. Lydia even suggests they turn off the automation in their home for a few days so she can cook and clean herself. She feels redundant in the absence of work. George doesn’t agree with Lydia’s suggestion.

After dinner that night, George visits the nursery again. The nursery is designed to learn the children’s emotions and wishes and simulate a reality accordingly. Because recently the lion hunts have increased, George wonders if the children are dwelling too much on death and violence. Previously, the nursery simulated other worlds the children desired, such as Alice’s wonderland or the land of Oz. For many months now though, the nursery has been the hot veldt. As the lions head towards him again, George shouts at the nursery to produce the world of Aladdin and the lamp, a story the children once loved. The room does not respond. A troubled George heads back to Lydia. Lydia thinks the children have filled the room with so many thoughts of Africa that “the room is in a rut.”

Wendy and Peter, ten-year-old twins, return from a party. George tells them “with false joviality” that he and Lydia have been traveling in Africa in the nursery, but the children deny the nursery is set to the veldt. Wendy goes off to the nursery, seemingly to investigate George’s claim. George rushes after her. By the time he and Lydia reach the nursery, it looks like a beautiful, green forest, with a girl called Rima in it. He asks the children to go to bed. He walks through the calm forest and spots his old wallet, bloodied, chewed up, and smelling of lions. It is obvious Wendy changed the simulation of the veldt right before her parents reentered the nursery.

George tells Lydia he now regrets buying their children the nursery. Lydia fears she and George may have spoiled the children. Peter and Wendy seem to grow angry whenever their smallest wish is not met. Lydia wants their friend, David McClean, a psychologist, to visit the nursery the next day and speak with the children. George agrees. He and Lydia hear loud screams and roars from the nursery. The screams seem to be from two people and sound familiar. The parents realize the children have reentered the nursery against their wishes.

The next morning, Peter asks George if he and Lydia plan to lock the nursery up for good. George tells Peter this wouldn’t happen if he and Wendy played with other simulations as well. Peter coldly tells his father that the nursery was supposed to be a place where he and Wendy could play as they wanted. When George warns Peter he and Lydia may shut down the whole house for a month, Peter threatens him against any such action.

David McClean comes over to inspect the nursery. The parents have let Peter and Wendy stay in the nursery so they can demonstrate their patterns for David to see. George and David ask Peter and Wendy to step out so they can examine the nursery. David feels something is very wrong with the nursery. Instead of nurturing the positive thoughts of the children, the nursery is bringing out their most destructive emotions and actualizing them. George should tear down the nursery and send Peter and Wendy for psychological counseling to recover. David tells George that he and Lydia have let the room replace them as parents for the children. The children now prefer the room—which gives them what they want—to their parents. This pattern must be broken immediately. George wonders if the nursery can come alive. Though David dismisses the possibility, George finds Lydia’s bloodied scarf on the floor of the nursery.

The children are apoplectic when George shuts down the nursery. To calm the sobbing children, Lydia suggests George turn it back for a while. However, George says the family has been enslaved to machines for too long and goes around the house switching off all automation. Peter seems to address the house, shouting for it to stop his father. When he and Wendy don’t stop crying, George relents to turn on the nursery briefly. The plan is to buy the parents half an hour before David comes over to help them move out of the house. Lydia and George are interrupted by the children begging them to come to the nursery. They rush to the nursery, which is empty. Wendy and Peter lock their parents inside. The lions circle George and Lydia, closing in for the kill. The parents recall why the screams they’d heard the previous night had sounded so familiar.

A while later, David comes over to the house. He heads over to the nursery and tells the children he can’t find their parents. The children smile at him and tell him their parents will be with him shortly. In the simulation of the veldt, David can see the lions fight over a fresh kill, vultures circling overhead. The shadows of vultures flicker across his face. Wendy offers David a cup of tea.