When recent Harvard grad Helen Zuman moved to Zendik Farm in 1999, she was thrilled to discover that the Zendiks used go-betweens to arrange sexual assignations, or “dates,” in cozy shacks just big enough for a double bed and a nightstand. Here, it seemed, she could learn an honest version of the mating dance—and form a union free of “Deathculture” lies. No one spoke the truth: Arol, the Farm’s...