Maomao is a young apothecary raised in the pleasure district before being kidnapped and sold as a servant in the imperial palace. Discreet and largely uninterested in court intrigue, she nevertheless draws attention thanks to her knowledge of medicine, poisons, and remedies when she solves several mysterious problems affecting the women of the palace. Noticed by Jinshi, a high-ranking official of the inner court, Maomao gradually becomes involved in cases involving illness, poisoning, rivalries, and political secrets, which she approaches with sharp observation and an analytical mind.