Taking the reign of Emperor Taizong Li Shimin of Zhenguan (627-649) as the core historical coordinate, it panoramicly restores the political ecology, clan rivalry, frontier diplomacy, economic system, cultural trends of thought, military strategy and social structure of the early Tang Dynasty. Based on this rich and vivid historical soil, it tells the story of a 21st century Tang historian who accidentally traveled into the body of a five-year-old boy in the third year of Zhenguan - the second son of Prime Minister Fang Xuanling, "Fang Yiai". The only "golden finger" he carries is a knowledge system and systematic thinking that transcends the times, not divine power or prophecy. He knows that history cannot be changed lightly, and he is not willing to become a pawn of power. He always embraces the hermit ideal that "success does not belong to me, but benefits to the common people in the future." He used modern rationality to awaken the potential of ancient institutions, but always respected the texture of history and the complexity of human nature. It depicts a stronger, more open, and more humane Tang Dynasty, and conveys a governance philosophy that transcends the times: the best change is when people do not feel the pain of change and only enjoy the fruits of change.
