The Dingyuan Marquis Manor was convicted overnight and the entire family was exiled. Because of a prophecy stating she would be the person most deeply loved and cherished by the emperor throughout his life, the legitimate daughter Cheng Mingyue was sent alone into the deep palace. As a maid in the Yiyou Court, she endured all kinds of humiliation and witnessed the wrongful death of her close friend. In the cold palace, she accompanied the abandoned and down-and-out sixth prince Zhou Hui, taught him to read and understand reason, tended to his sickly and weak body, relied on each other for survival, and helped him step by step to ascend the imperial throne. Yet after donning the dragon robe, youthful deep affection ultimately had to be weighed against imperial power, the family's old grievances remained hard to clear, and the true meaning of that prophecy always remained hidden in the moonlight of the deep palace.