Jiang Shu, a maidservant in the Prime Minister's mansion, becomes a trial marriage maid for Mu Qiyi, the heir of the Marquis of Wu'an, in order to escape her slave status. However, during her mission, she mistakenly identifies Shen Wuwang, the head of the Northern Prison, as her savior. Mu Qiyi uses Jiang Shu to test Shen Wuwang's secrets, while Shen Wuwang secretly protects her because of their past relationship. Jiang Shu gradually discovers the truth, confirming from the details of the gold medal that Shen Wuwang was the one in the boudoir that day, and resolves to resist Mu Qiyi's manipulation. Shen Wuwang gets caught up in a power struggle to protect Jiang Shu, and the two join forces to fight against Mu Qiyi's conspiracy and expose the truth behind the Wen family's wrongful conviction. In the end, Jiang Shu risks her life to save Shen Wuwang, escapes her slave status, and the two start a new life together, jointly managing the Northern Prison and a business, achieving a double fulfillment of freedom and love...
