This Time of Darkness.
Amy and Axel are children living in a decaying and decrepit City. Amy was born there but is different from the others in that she has learned how to read (illegal in the City). Axel is a troubled boy who eventually claims to Amy to have come from "Outside". Together, she and Axel embark on a trip to find a way to Outside and to Axel's home and family. They will learn much of their world and about themselves on a long journey through many trials and hardships.