Centuries after most of humanity died out, a new civilization is slowly constructed upon the remnants of the old.
Emery, a young man living in the walled city of Rittenhouse, has taken it upon himself to rescue "mutts," as the citizens of Rittenhouse call the impoverished masses outside. When Timothy, a boy afflicted with a fatal illness, seeks Emery's help, the two embark on a deadly errand to secure the medicine Timothy needs. This mission takes them from the safety of Rittenhouse into the wasteland outside it, where ancient superstitions are reborn and humanity struggles to survive amidst the ruins of a fallen American metropolis.