Xiao Chengyan, a modern man, wakes up to find himself transmigrated into the body of a gravely ill, foolish emperor of the Great Yin Dynasty. The entire imperial court has gone completely mad: the Noble Consort wants a border general executed to pay for her cat's life, the Crown Prince releases an enemy nation's hostage prince under the noble excuse of 'winning him over with love,' and the imperial censor demands that the emperor apologize to an assassin. Meanwhile, the Left Chancellor, Pei Huaien, secretly controls the government and is simply waiting for the emperor to die so he can tear the Great Yin Dynasty apart. But Xiao Chengyan refuses to let them have their way. He first reopens the cat case, then deposes the Crown Prince, cracks down on the ambitious chancellor, and restores the Empress to her rightful position after years of neglect. With his modern knowledge and iron-fisted methods, he not only brings the deranged officials to heel but also leads a northern campaign against the grasslands and secretly investigates Jiangnan, turning a kingdom on the brink of collapse into the beginning of a new golden age!