Josh Overstreet and his sister Claire have been carving a life out of the ash for more than half a decade, unsure whether anyone yet lives outside the small valley where they have established their town of Overstreet with two dozen others. Then Deanna Pembleton stumbles into the valley, asking for help for herself and her friends. Claiming they have eked out a life much like that of the people of Overstreet, she begs assistance, which Josh is willing...