Book excerpt: The essays in this volume are written by clinicians, psychologists, sociologists, educators, parents and de-transitioners. Contributors demonstrate how ‘transgender children and young people’ are invented in different medical, social and political contexts: from specialist gender identity development services to lobby groups and their school resources, gender guides and workbooks; from the world of the YouTube vlogger to the consulting rooms of psychiatrists; from the pharmaceutical industry to television documentaries; and from the developmental models of psychologists to the complexities of intersex medicine. Far from just investigating how they are invented the authors demonstrate the considerable psychological and physical harms perpetrated on children and young people by transgender ideology, and offer tangible examples of where and how adults should intervene to protect them.