"At fourteen, Kelsey Osgood became fascinated by the stories of women who starved themselves. She devoured their memoirs and magazine articles, committing the most salacious details of their cautionary tales to memory--how little they ate, their lowest weights, and their merciless exercise regimes--to learn what it would take to be the very best anorectic. When she was hospitalized for anorexia at fifteen, she found herself in an existential wormhole:...