A few hundred years after the One State's conquest of the entire world, the spaceship Integral is being built in order to invade and conquer extraterrestrial planets. Meanwhile, the project's chief engineer, D-503, begins a journal that he intends to be carried upon the completed spaceship. Like all other citizens of One State, D-503 lives in a glass apartment building and is carefully watched by the secret police, or Bureau of Guardians. D-503's lover, O-90, has been assigned by One State to visit him on certain nights. She is considered too short to bear children and is deeply grieved by her state in life. O-90's other lover and D-503's best friend is R-13, a State poet who reads his verse at public executions.