The action in the book starts innocuously enough with a group of six people taken into the woods by a small tour company, Mystic Tours, for a sort of Native American sweat-lodge-inspired purification ceremony. After the group is abandoned by their putative guide, John Lightfoot, they're left to their own devices in the face of limited food, struggles over what exactly to do, and the lurking perils of both the forest and the human mind.