Short Short Short Version
Parents use technology to spoil their kids—and then the kids use technology to kill their parents (maybe).
Longer Version (Now with Names)
Lydia Hadley tells George that she's worried about the nursery, which is this awesome virtual reality room where kids and adults can go off on any adventure they want. (Do you know the Star Trek holodeck? It's pretty much that.)
See, the Hadley family live in this awesome automated house that does all the work for them. Which leaves them lots of free time to feel bad about themselves. This is mid-century America, so everyone feels bad about themselves. Ever watch Mad Men? It's like that, minus the ever-handsome Don Draper. Then again, maybe George is a looker.
The kids Peter and Wendy are spending lots of time in virtual Africa, with lions who always seem to be eating. This makes Mama Lydia nervous, because she thinks fake lions can kill her. Ha! There's no way that will happen, right? Hasn't she ever heard of a TV before?
Peter and Wendy are very independent kids. Today, that would go on their college essay, but in the 1950s, it's, well, less than ideal. They talk back to their parents (someone call the cops!), and George and Lydia worry that maybe they've spoiled the kids. George invites psychologist David McClean to come give his opinion, the lesson here being that doctors' opinions are better than wives' opinions. At least, according to George.
The doctor is in. David tells the Hadley parents that they messed up big time and need to turn off the nursery. But before David can get them all to go on an actual vacation (and not just a virtual safari), the kids beg the parents to let them use the nursery one last time. And then the kids lock their parents in with the fake lions.
When David McClean comes back, he sees the lions eating… something.