Zhao Heng, a graduate student in the Department of History, was transformed into the deposed prince of the Northern Yan Kingdom and was imprisoned in the cold palace for ten years, pretending to be crazy and selling himself a fool to survive. In an accident, he rescued Su Jinglan, the daughter of the Marquis of Zhenbei, who was disguised as a man, and the two teamed up to investigate the military pay corruption case. When Zhao Heng's modern notes were discovered by Hanlin Jiang Mubai, the identity of the deposed prince was exposed, and the civil and military officials of the court were shocked. Wei Zhongxian, the admiral of Dongchang, wanted to kill him, Prince Zhao Yu secretly planned it, and Chu Yao, the saint of southern Xinjiang, used bewitching to disrupt the situation. Under siege from all forces, Zhao Heng relied on historical knowledge to accurately break the situation, and was eventually begged by the officials to ascend the throne. However, he discovered that there was a greater dynasty secret buried under the throne.
