Rich girl Yang Jiazhen (Ma Li) married Li Mao (Chang Yuan), a small detective. Although they loved each other, they were never recognized by Jiazhen's parents. Li Mao unexpectedly discovered that he looked the same as the prince. One wanted to enter the palace to get a promotion, and the other wanted to leave the palace to gain freedom. The two exchanged identities, but they were unaware that they were being drawn into the Shangshu's conspiracy step by step...