How It All Goes Down
Here in the future, life is wonderful, just like they promised. Everyone knows their task and understands their part in the great purpose, and we even shave our heads and use numbers as names to avoid anything even remotely resembling individualism. And hey, since we've conquered the whole world (except for that weird creepy part beyond the wall), we may as well fly to other planets and do the same thing to the aliens we find there. Won't that be fun?
That's the thinking of the intriguingly named D-503: mathematician and rocket scientist who's thrilled to be a part of the program. (And yes, you may note a disturbing resemblance to Emmet, the hero in The Lego Movie.) He writes a diary trying to convince anyone who reads it of the awesomeness of the One State, the society in which he lives.
He runs into trouble when he meets the sultry I-330 on an assigned walk. She does horrible things like flirt with him instead of filling out a formal request for a Booty Call in triplicate like the State requests. Repulsed and yet strangely attracted to her—there's something about a bad girl—D-503 accompanies her to the museum-like Ancient House, which is the only building in the whole world that doesn't use windows for walls. He plays hooky from work to do it—a serious no-no in this world—but refuses when I-330 offers to have an excuse written up for him by a corrupt doctor.
He's gonna denounce her to the state. He really, really is. But…
He starts having dreams. This is also forbidden by the state—in fact they're considered a form of insanity—but apparently no one consulted his subconscious on the matter. It also makes him less willing to turn in I-330, which is a good thing when she reveals that she belongs to MEPHI, the resistance movement du jour. (There's always one of them in these kinds of stories…). Again, he refrains from finking on her, and she takes him through a secret tunnel under the Ancient House to the world outside the wall. There, people grow hair and wear cavemen furs and have sex without their neighbors looking in and all kinds of other inappropriate things the One State wouldn't like. I-330 and the other members of MEPHI want to blow up the wall and reunite humanity.
Trouble arises when D-503's state-sanctioned lover, O-90, begs him to give her a baby even though the government forbids it. D-503 goes along with it when she promises to turn the baby over to the state for raising, but once impregnated, O-90 decides that life with the cavemen would be easier. D-503 and I-330 smuggle her outside the wall.
Sometime after that, D-503 undergoes a fun new operation—that everyone gets to go through—that completely burns all of the emotions out of his brain. When they're done, he cheerfully tells them all about MEPHI and his various zany undertakings with them. I-330 gets arrested, but not even torture gets her to break and she goes to her death without regrets. This should probably upset D-503, but that whole lobotomy thing really seems to work.
Meanwhile, MEPHI's been awfully busy and even with D-503's betrayal, their great work is underway. Parts of the wall have collapsed. Birds are returning to the city. Riots are breaking out and those pesky emotions the State is trying so hard to stamp out seem to be reasserting themselves. D-503 expresses hope that the State will triumph, but it doesn't look good.
Revolution, it seems, is always just a few well-organized malcontents away.