In the east lies a kingdom governed by an emperor with his concubines and attendants residing in a grand palace known as the hougong, or rear palace. Maomao, a modest girl from a small town raised by her pharmacist father, never imagined that the rear palace would play any role in her life until she was abducted and sold into service there. Despite her unassuming appearance, Maomao possesses a sharp intellect, quick wit, and extensive medical knowledge. Her secret is revealed when she crosses paths with Jinshi, the head eunuch of the palace, who recognizes her abilities and makes her a lady-in-waiting to the Emperor's favorite concubine. Her new role involves tasting the lady's food for poison. As she learns more about life in the rear palace, Maomao discovers that not all of it is wholesome. Will she be able to lead a peaceful existence or will her powers of deduction and insatiable curiosity lead her on more adventures and dangers?