Teenager Bola Craftentech and his two sisters are caught in the midst of a class struggle between the Cleans and Workers of their world. They live in a society that has cloned people to ensure that skills and blood lines remain intact. The Cleans are the elite crafters, scholars, and artisans who rule Central City. The Workers are the support cast who live and work beneath the city in the tunnels below. Because the children are natural born children with a parent from each faction, they bridge both worlds. The death of their parents has thrust them into the unfamiliar world of the tunnels where they now struggle to eke out a mere existence.