Shen Yanning, daughter of a general's family, enters the palace by imperial decree to become empress, but on their wedding night she faces the cold indifference of Emperor Xiao Yu. Amidst the loneliness of the deep palace, she crosses paths with a mysterious man who looks identical to the emperor, mistaking him for a shadow-emperor whose identity was erased, and names him Xiao Che. Treating him with utmost sincerity, Shen Yanning teaches him how to carry himself like an emperor and even incites him to take the throne. Little does she know, the "shadow" accompanying her every night is none other than the emperor himself, Xiao Yu. A game of deep palace displacement and tension quietly unfolds between lies and testing.