In a devastated cityscape, a lone man fights off creatures of fearsome power: white, winged, serenely impassive, and capable of terrifying transformations... Decades later, in a desolate American southwest, a meager colony of human survivors ekes out a precarious existence between dwindling water supplies and magnetic shields that screen them from roving bands of aerial attackers. An ancestral upper class presides, while in the lower city, laborers do the hazardous work of keeping everyone alive. But all that may be about to change when the mysterious Joshua comes of age.