In the year 241, twelve-year-old Lina trades jobs on Assignment Day to be a Messenger to run to new places in her decaying but beloved city, perhaps even to glimpse Unknown Regions.

While visiting the small town of Yonwood, North Carolina, eleven-year-old Nickie makes some decisions about how to identify both good and evil when she witnesses the townspeople's reactions to the apocalyptic visions of one of their neighbors.