A modern person, Lu Yuan, time-travels to become the Ninth Prince of Dayong. As the legitimate son left behind by the late Empress, he should have been one of the most powerful contenders for the throne. However, he has no interest in power whatsoever and only wants to stay away from the capital and become a carefree prince in his fief. Yet, the Second Prince, Lu Cheng, fearing that Lu Yuan would threaten his position as crown prince, conspires with Noble Consort Shen and the Shen Group to set up traps and frame him repeatedly. The more Lu Yuan tries to concede, the more aggressively the other party presses on. To protect himself and those around him, he has no choice but to hide his brilliance, fight back to seize the throne, and use modern knowledge to improve technologies such as horseshoes, stirrups, saddles, cement, and refined salt, gradually winning the Emperor's regard.