Popular culture is full of post-apocalyptic visions these days, especially the fiction and movies aimed at young adults. The plot usually features a variegated band of survivors crossing a wasteland in search of a place of peaceful plenty that may or may not exist. Ruined cityscapes poke out of the sand. The survivors have nothing in common and don't even get along well with each other, at least at first. The communities they encounter along the way tend to be militarized dictatorships, patriarchal cults, or cannibals. There is a mysterious, lanky man in scuffed boots who claims to know the way, on the basis of arcane knowledge from Before.