Set during the reign of King Sukjong in the Joseon dynasty, the series is based on the historical character Consort Suk. The story focuses on Dong Yi, a slave maid working in the Bureau of Music. Her warm personality, sincerity and exceptionally keen mind help her in solving difficult court intrigues and allows her to rise in the ranks, first as a Lady of the Court then a Concubine, despite being Lowborn. While solving a case she meets the King who introduces himself as a Police Officer. He enjoys her treating him as a real police officer and he falls in love with her. She also gains the favor of Queen Inhyeon and meets Jang Hee Bin, another concubine who is first an ally then becomes her bitter enemy. In her quest to survive in court and bring justice to the Lowborn, she makes many allies, among them: Cha Chun Soo (who she considers an older brother though not blood-related), Seo Yong Gi (Police Chief), and Court Ladies Jung and Bong
