George and Lydia Hadley think something is wrong with the “nursery” in their expensive Happylife Home. The Happylife Home is a futuristic house that automates almost every human routine: it cooks and cleans, turns lights on and off, transports the Hadleys to their bedrooms via an “air closet,” and even rocks them to sleep. As the kitchen automatically makes dinner for them, Lydia asks George decide to take a look at the nursery, or call a psychologist to examine it.
The Hadley parents walk to the nursery, which turns out to be a virtual reality environment—a room that can immerse users (in this case, the Hadley’s children) in a virtual world of their own imagining. It does this by receiving “telepathic emanations” from the children’s minds. In the nursery, a perfect, three-dimensional rendering of an African veldt surrounds George and Lydia. They observe vultures above and lions in the distance, feeding on something. Lydia hears a scream, but George, in awe of the “mechanical genius who had conceived this room,” doesn’t notice.
The lions approach George and Lydia, “feverishly and startlingly real.” As the lions break into a run toward the couple, Lydia screams and they both run out of the nursery. While Lydia cries in terror, George laughs and consoles her, saying that none of it is real. But Lydia replies that it feels too real. She demands that George lock the nursery and tell the children, Wendy and Peter, to stop reading about Africa. George agrees and locks the door; he suggests that Lydia has been working too hard and needs to rest. Lydia replies that, on the contrary, she hasn’t been working at all. She proposes that they shut off the Happylife Home and take a vacation. She expresses the desire to perform normal human tasks again, to once more feel “necessary.”
Later, George enters the nursery again and reminisces about the times when his children would imagine wonderful fantasy scenes. Now, the veldt that they have created doesn’t feel as good. He reflects that there is too much death in the veldt, and it can’t be good for the children to get in the habit of imagining death (while at the same time musing that children naturally think about death without really understanding it). He tells the nursery to make the veldt go away, but it doesn’t respond.
The parents confront their children about the African veldt, but Wendy and Peter play dumb, insisting they don’t know about any veldt. Wendy manages to run to the nursery and change the scene before George and Lydia can see it again. They send the kids off to bed. Then George finds one of his old wallets in the nursery, chewed up and bloody. He locks the nursery door.
In the middle of the night, George and Lydia talk and agree that their children are openly disobeying them; they have been spoiled, and must now be disciplined. They decide to invite their friend, psychologist David McClean, to take a look at the nursery. Then they hear eerily-familiar screams coming from the nursery, and realize the children have broken in through the locked door.
The next day, Peter asks George not to lock up the nursery. George tells him that he and Lydia are considering turning the whole house off and for a month. Peter thinks this is an awful idea, saying that he hates the prospect of tying his own shoes and grooming himself. He issues a vague threat to George before going back to the nursery.
David McClean arrives to look at the nursery, and says that it doesn’t “feel good.” He recommends that they destroy the room and bring the children to him for treatment. He explains that the nursery “‘has become a channel toward destructive thoughts,’” and that it has become more important to Wendy and Peter than their actual parents. Together, David and George turn off the nursery.
Wendy and Peter become extremely upset. As George turns off the rest of the Happylife Home, turning it into “a mechanical cemetery,” the children cry and beg for one more moment in the nursery. George acquiesces, and the children go in, momentarily appeased. George and Lydia are upstairs changing when they hear their children calling for them. They run into the nursery and the children, having set a trap, lock them inside. The parents scream as the lions in the nursery kill and eat them. David McClean arrives to help the family settle into their “vacation” from the Happylife Home, but instead sees Wendy and Peter in the veldt, having tea.