In some ways, this novel tells a familiar story, about a white middle-class girl who detours destructively before she can fully come of age. But it does two things differently: first, it interweaves the style of popular girl narratives like The Baby-Sitters Club and Girl, Interrupted, with an adult auto-theory conclusion in the style of Chris Kraus.The protagonist’s coming into queerness and transness is mirrored by the book moving through the predominantly straight genres that shaped her. The second difference is that Margaret leaves girlhood not just by aging out, also by transitioning to a new gender. This novel is written from the author’s own retrospective transmasculine perspective; it is a tribute to the author’s heritage of girl literature, as well as a groundbreaking revival of a beloved literary mode. In this way, this book attempts to make space for the genderqueer and not-yet-transmasculine in the literature of the girl.Transmasculine, genderqueer, and nonbinary writers and characters get left out of the literary discourse on girls all the time. In Margaret and the Mystery of the Missing Body, the deferral of adulthood takes the form of an eating disorder-an overwhelming trope of the nineties. We’ve recently seen a slew of media waxing nostalgic for the decade.This book is more critical than nostalgic. It interrogates some of the most injurious aspects of the nineties in the US: antifeminist backlash, post-AIDS homophobia, slut shaming and sex-negativity, and, of course, the eating disorder crisis-all of which made nineties girlhood a pretty toxic environment. However, the current wave of nostalgia has not properly reckoned with this, and there is still much left to be properly digested.