The book opens with Samuel Pepys, a naval administrator living in London in the 1660s. His candid diary relates the fatal illness of his brother, Tom, who allegedly died of the pox - or did he? The Introduction uses Pepys’ complex reaction to his brother’s ailment, including attempts to get a doctor to make a new diagnosis to clear the family name, as a way into the book’s central themes of deception, shame, unlawful sex, and the essential unknowability of venereal disease. The Introduction provides an overview of the history of disease that lays the groundwork for why the stories in this book matter and how they present evidence of seemingly modern ways of viewing and responding to diseased bodies nearly a hundred years earlier than historians presumed. It then situates the book in the history of medical retailing, sexuality, and the print trade, and ends with a discussion about the history of everyday urban life amidst epidemic disease.