Vashti is a small, pale woman who lives entirely within a subterranean, mechanized room resembling a bee's cell. She relies completely on the Machine for all her physical, intellectual, and social needs. She spends her time giving and listening to remote video lectures on obscure topics like Australian music. She finds physical travel and the natural world highly unpleasant, preferring the comfortable existence provided by her button-operated environment.

Kuno is Vashti's youngest son, assigned to live in a room on the opposite side of the world. Unlike the deeply sedentary population, he possesses a restless curiosity and an unusual degree of physical strength. He is fascinated by the natural world, particularly the stars, and harbors a deep dissatisfaction with the isolation of life inside the mechanical system. He applies for permission to become a father but faces rejection from the authorities.

The Machine is an omnipresent mechanical system that governs every aspect of human life. Built to provide ultimate comfort and safety, it has gradually stripped humanity of its independence, physical strength, and connection to nature. Citizens increasingly treat it as a divine entity, relying on it entirely for food, communication, and basic survival while remaining confined to their isolated underground rooms.

The attendant works aboard the rarely used airship that transports citizens across the globe. Because her job requires regular face-to-face communication, she stands apart from the standard isolated population. She retains traces of outdated social customs, such as attempting to physically assist her passengers when they lose their balance, which is considered a severe social breach.

A prominent intellectual figure within the society who delivers remote lectures to the populace. He advocates for the absolute superiority of secondhand sources and interpretations over direct observation of the physical world. He acts as an ideological mouthpiece to pacify the population and discourage direct interaction with nature, urging citizens to trust the system completely.

The Mending Apparatus functions as the repair arm of the Machine, tasked with maintaining structural integrity and enforcing order. Manifesting as a mechanical, worm-like entity, it guards the physical boundaries of the underground world. Its primary directive is to seal breaches and prevent unauthorized access to the earth's surface.