In the 23rd century, humanity has been decimated by war, overpopulation, and pollution, forcing the survivors to live in a giant domed city. Here, a powerful AI ensures a hedonistic lifestyle, providing for all basic needs. In this society, babies are born in artificial chambers using donated sperm and eggs, and each newborn has a gemstone encrusted on their palm that changes color with age.

When a person turns 30, their gemstone turns red, signaling their termination in a public ritual called the "Carrousel." Most citizens believe this process renews them as newborns, but a group of dissenters suspects it's merely a death ritual and part of the AI's propaganda.