One day in 2009, twenty-four-old Susannah Cahalan woke up alone in a strange hospital room, strapped to her bed, under guard, and unable to move or speak. A wristband marked her as a "flight risk," and her medical records, chronicling a monthlong hospital stay of which she had no memory at all, showed hallucinations, violence, and dangerous instability. Only weeks earlier, Susannah had been on the threshold of a new, adult life, a healthy, ambitious...

"If I could take what I've learned and make one menial job easier for you, or prevent you from having the kind of sex where you feel you must keep your sneakers on in case you want to run away during the act, then every misstep of mine was worthwhile. I'm already predicting my future shame at thinking I had anything to offer you, but also my future glory in having stopped you from trying an expensive juice cleanse or thinking that it was your fault...