In eighteenth-century Joseon, officers Lee Jong-won of the Left Police Bureau and Yuk Joong-chang of the Right Police Bureau belong to rival institutions and investigate in very different ways. When sacred roof tiles disappear from a royal shrine, the two lawmen are ordered to cooperate before the theft reaches the king’s ears. The case expands into suspicious deaths, missing letters, powerful families, political interests, and early investigative methods. Drawing on real historical records and figures, the novel combines carefully researched faction storytelling with lively buddy-cop chemistry, transforming Joseon law enforcement into a richly detailed world of deduction, rivalry, humor, and crime.