Helper12 works as a Baby Helper in Pre Ward, the place where babies spend their first six months of life before they're tracked for vocations and sent to training. One day, the Sloanes, Society members who enjoy all the privileges - a private dwelling, access to good food and good schools - come to "adopt" one of the Pre Ward babies. The Director makes a deal and the Sloanes walk out with a brand new child. They also walk out owning Helper12 - the Director sells her to them, and there's nothing she can do but go.
Twitch was born into the system: the system of Society members and lower designates. Unfortunately for her, she belongs to the latter group. Lower designates are tracked for a task and expected to do what they're told, when they're told, from birth on. Twitch has never known anything different. She lives her life from day to day, working at the Pre Ward, trudging home to the complex at night, following the rules because to defy them means imprisonment, or even death. Still, when her only real friend mysteriously disappears, Twitch asks one too many questions.