It’s a hundred years from now. The human race has paid a steep price for our wanton destruction of the environment: climate change has wreaked havoc worldwide, causing the oceans to flood and temperatures to rise to unbearable levels. Most of our species has been wiped out, but a small group of survivors took shelter in what was once a zoo: they’ve made this former zoo into an airtight “habitat,” which has become a sealed-off, authoritarian society.
Elder Constance, the society’s leader, informs her advisors, Elizabeth and David, that the law which forbids any inhabitant to leave the Habitat has become permanent. They had hoped to be able to go outside again, she says, but it’s just not worth the danger of dealing with Nature again.
Two kids, Lydia and Jake, overhear this pronouncement, and react with anger and frustration. (Lydia is David’s daughter, and Jake is Elizabeth’s son.) They’ve been waiting their whole lives to go outside, and now it looks like they’ll never get the chance.
The Bonobo, a giant ape who lives in the exhibit next door, suddenly addresses them. Lydia and Jake are shocked that the Bonobo can speak; the Bonobo says wearily that he’s “learned your language through overexposure.” The Bonobo hints that he has secrets to tell the kids…
…but the Elder bursts back in and furiously reprimands the kids for talking to the Bonobo. She summons their parents, whom she humiliates. When Elder Constance leaves, Lydia and Jake ask their parents what she’s so worried about.
Elizabeth and David tell their children, finally, the true story of how they ended up in the Habitat. They’d always told their kids that human beings wanted to seal themselves off from Nature, but now they guiltily admit that they had to flee to save their lives.
When their parents leave, Lydia and Jake argue about whether it’s worth running away to try to see what Nature’s like (Lydia votes yes, but the idea freaks Jake out). The Bonobo interrupts them, and offers them something he’s been illegally growing in his exhibit: real fruit, which is totally unlike the synthetic food the kids have grown up on.
Lydia tastes the fruit first, then offers it to Jake. They are overwhelmed by its freshness, its richness, its reality.
They hatch a plan to escape the Habitat: the adults dispose of the society’s trash by tossing it down a garbage chute, so the kids will jump down the chute. Lydia realizes it’s trash day, and the kids prepare to make their escape.
Elder Constance bursts back in. She’s livid when she sees the kids plotting with the Bonobo, but even more so when she sees that they’ve eaten real fruit. She seems almost devastated, in fact. She summons Elizabeth and David and tells them that their children must be banished.
Lydia and Jake say that was exactly what they were hoping for: they want to see what’s worth saving out in the real world. Elder Constance tries to change her tune and force them to stay – but Elizabeth and David stand up for their kids’ newfound bravery and curiosity. Bitterly, grudgingly, Elder Constance agrees to let the kids free.
For the first time in their lives, Lydia and Jake witness the main door of the Habitat being opened. Slowly but surely, they make their way out into the world.