Regent Gu Yanzhi has a secret: he can't stand bitterness. As a boy, he suffered from a lack of food and medicine in the cold palace, leaving him with a lingering ailment and a hatred of the bitter taste of all medicinal brews. Shen Yunqing, a “little mute” born into a family of physicians, is sent to the prince's residence by his clan as a “living medical compendium,” but in truth, he is a hostage. At first, Gu Yanzhi regards him as nothing more than a rare medicinal herb that must be carefully watched. Then he notices that whenever the boy brings him his medicine, he always “happens” to leave a dish of sweet preserved plums on his desk, or a cup of mellow osmanthus wine. From then on, the medicine no longer goes down so hard. He begins indulging Shen Yunqing's “unannounced visits” to his study. Beside mountains of official documents, the boy quietly reads medical texts, occasionally reaching up to massage the throbbing ache in his forehead. As political storms rage, Gu Yanzhi shields him with his own body, deflecting every attack, overt and covert. He sets aside the rear courtyard of the prince's residence as a garden of medicinal herbs, letting Shen Yunqing wander as he pleases. Later, after Gu Yanzhi clears every obstacle and the Shen family wants to take back their legitimate son, the usually gentle prince tears up the memorial in open court. Before the eyes of everyone present, he gently places a jade hairpin symbolizing the title of princess consort in Shen Yunqing's hair.
