From the beet fields of North Dakota to the wilderness campgrounds of California to an Amazon warehouse in Texas, people who once might have kicked back to enjoy their sunset years are hard at work. Underwater on mortgages or finding that Social Security comes up short, they're hitting the road in astonishing numbers, forming a new community of nomads: RV and van-dwelling migrant laborers, or "workampers." Building on her groundbreaking Harper's cover...

Area X has claimed the lives of members of eleven expeditions. The twelfth expedition consisting of four women hopes to map the terrain and collect specimens; to record all their observations, scientific and otherwise, of their surroundings and of one another; and, above all, to avoid being contaminated by Area X itself.