Abriel Brighton exists solely to give birth to genetically perfect children-a role she has no interest in fulfilling. Created by the scientists who originally settled on and colonized a dead planet with the intention of terraforming it, she belongs to a breed of genetically altered humans designed to safe-guard humanity's DNA. Living in a protected underground society called Urbine's Crescent, she and others like her are to be retrieved once the surface is ready for habitation. However, they've been waiting a long time. Long enough that the idea of the surface world has faded into legend. When Abriel's father is murdered, she finds herself thrust into a conflict where all motives are suspect. As a scout and pair-bonded with a telepathic dog-like animal that's native to the planet, she struggles to determine the responsible party. Instead, violence escalates to the point where law becomes meaningless and she's stripped of all power. Worse, Abriel discovers the Crescent leadership is systematically destroying the only home she's ever known and her enemies are probably her only allies. When a stranger named Porter arrives, claiming to be from the surface and delivering the message that the planet is terraformed and ready to support human life, she has no choice but to believe him. Without his help, the Crescent won't survive. But with it, they just might be able to remake their entire world.