A modern man accidentally travels to the Tang Dynasty, hoping only to laze around in his country estate. But his hotpot, improved plow, and uncanny foresight catch the attention of the empress in disguise. Forced into a sworn brotherhood with the emperor posing as a grain merchant, he secretly introduces relief programs, banks, and new crops—defusing crises from invasions to smallpox. After bankrupting noble families with glassmaking and saving a princess with a vaccine, the emperor's true identity is revealed. Offered a title, he just wants to escape: "Don't disturb my retirement!" Unaware he's already become the dynasty's hidden guardian.
