Beans Velocci traces the history of current high stakes attempts to define sex and to create a world devoid of trans life. Drawing on lab notes, family genealogies, medical case studies, and more, Velocci demonstrates how the practice of sorting of bodies into male and female shifts based on changing understandings of race, anatomy, and research and medical methodologies. They demonstrate that it is not the cis people who fit the categories; it is the categories that flex to make them fit.