Out of the collapse of Old America rises Lantua, a glittering thousand-mile metropolis where drones patrol the sky and AI algorithms reward social behavior. The most compliant citizens enjoy the greatest privileges, the poorest struggle to rise up the echelon system, and criminals are subjected to brain modification. Birthing and genetic quality are controlled through mass embryonic selection, with fetuses grown outside the body in artificial wombs—a technology known as exogenesis.

But rebellion is brewing.

Lantua struggles to control the Benedites, a rural religious people who refuse to obey one-child regulations. Each February, Field Commander Maelin Kivela oversees the forced sterilization of Benedite teenagers, a duty she carries out with unflinching zeal—but this year comes with a shock. After escaping an ambush by insurgents, Maelin returns to the city to choose one of over three hundred embryos to be her child, only to come face to face with a secret that will tear her life apart and alter the course of her civilization.