In “Chapter Three,” Lee studies texts that convey the notion that if armed with knowledge about the distinguishing features of Conversos, Old Christians could become proficient at identifying even the most sophisticated veneer of sameness. Lee focuses on religious and medical treatises aimed at rendering the Converso body as subhuman and tainted. These prescriptive texts written by theologians Pedro Aznar Cardona, Vicente da Costa Matos, Francisco de Torrejoncillo, and the medical doctor Juan de Quiñones argued—making extensive references to biblical, classical, and scientific sources—that Jews and Conversos exhibited their sinfulness through physical signs, such as elongated rears, skin eruptions, and/or suffered from periodic anal bleedings. Lee also examines Libros verdes, anonymous genealogical catalogues aimed at exposing the hidden Converso taint in the ancestries of distinguished families.