Maomao walks into a room and immediately knows what's wrong with you, which should be insufferable until you realize the show isn't interested in making her likable, it's interested in what happens when someone too smart for the world around her gets trapped in it anyway. The mystery plotting pulls you forward, but the real gravity is watching her and Jinshi circle each other, two people who understand the palace's rot so completely that honesty becomes their only weapon. The visuals are so precisely composed that a single shot of someone's hands tells you everything about their poison of choice.

Maomao's life as an apothecary's daughter in the capital's pleasure district ends when she is kidnapped and sold into service in the rear palace, where the emperor's consorts live. Stuck at the bottom of the court as a maid, she keeps her deep knowledge of medicine to herself so no one takes notice of her. When the emperor's infant children fall seriously ill, she works out the cause and tries to pass on a warning without giving her name. Jinshi, the perceptive head eunuch, sees through her and promotes her to lady-in-waiting for Gyokuyou, the emperor's favorite consort, which includes tasting the lady's food for poison. As Maomao treats one ailment after another at court, her skill with medicine soon makes her indispensable in this drama built around mysteries.