During the war between Sheng and Yu kingdoms, Sheng was defeated. On her deathbed, the Sheng princess tasked her maid, A Yue, to impersonate her, marry for peace, and steal Yu’s defense map. Meanwhile, in Yu, Prince Chu Ru Heng, branded a “rebellious son,” seeks the truth behind his mother’s mysterious death. A "fake princess" and a "disgraced prince" cross paths in a treacherous palace. Amid suspicion and love, they join forces to uncover secrets and fight for peace.