Forced to go on a hiking trip with his Uncle Jack, fourteen-year-old Zach Walker heads to the desert near Bluff, Utah to search for an ancient staircase—the same one Zach’s father was looking for when he disappeared three years before. Once in the backcountry, Zach discovers prehistoric ruins, mysterious rock art, and a one-way portal to the past. When he steps through the portal, he finds himself trapped in the land of the Ancestral Puebloans—a place hit hard by severe drought and conflict. Zach soon runs out of food and water, but a native girl...