At the beginning of the Western Han Dynasty, on the eve of her wedding, a Chang ' an singing girl named Dou Yifang met Crown Prince Liu Heng who was persecuted by Empress Lü. She used her fiance's tiger to save him out of the city, which resulted in all members of her husband's family being executed, and she herself was sent to the palace as a slave. She designed a plan to switch the son of Concubine Wang with the daughter of Empress Lü's - Empress Zhang Yan. Empress Lü appreciated her intelligence and competence, so under the name of giving away a daughter in marriage, she sent her to the State of Dai to monitor Liu Heng and his mother. For the common people no longer to suffer, and for Empress Lü to trust her more, Yifang suggested that Liu Heng secretly train soldiers under the name of building a palace, which made everyone think that she was a temptress.