Three hundred years ago, the physician Hengwu Sanren prescribed a dose of carefree grass for A Heng, a patient suffering from lovesickness. After taking it, she forgot all her pain and also forgot the person who prescribed the medicine. He exhausted all his cultivation and was reduced to a mortal, remembering only that her name was A Heng. Three hundred years later, Lu Heng, the manager of Hundred Herbs Hall, guards a name, a medical prescription, half a bottle of remaining medicine, and thirty seeds, quietly acting as his mortal manager. Until the carefree grass sprouted, and flowers unseen by anyone in three hundred years bloomed.