In her previous life, Crown Prince Pei Ye took a drug to feign death on his wedding night for his beloved Qin Zhenzhen, leaving Crown Princess Shen Wanning with the terrible reputation of being a husband-killer and causing the Shen family to suffer exile. Two years later, Pei Ye returned in grand style with a pregnant Qin Zhenzhen and ordered Shen Wanning to be executed, having her body discarded in a mass grave. Reborn, Shen Wanning returns to her wedding night. With the fake-death drug taking effect, she decisively poisons Pei Ye unconscious and locks him in a hidden compartment beneath the bed. She then seeks out Yan Ci, a wandering swordsman whose appearance is identical to the Crown Prince's, and has him take Pei Ye's place! The two strike a three-month cooperation agreement, and Shen Wanning personally teaches Yan Ci how to impersonate the Crown Prince as they join forces to navigate the dangers of the Eastern Palace.