Modern man Shen Nan is brought into ancient times by an official seal, facing food shortages, plagues, late spring cold snaps, and the heavy encirclement of corrupt official Zhou Mao, the prefect, and foreign spies. He travels back and forth between different realms to procure food, fights bandits, cures epidemics, refuses to hand over the core formula, cleverly defeats the spies, leads the refugees to build reservoirs, make cement, and promote agriculture, teaching people how to fish. Promoted from county lieutenant to prefectural governor, he builds Anmin Prefecture. After his immortal magic is exhausted, he still relies on the common people and science to save himself. As Shen Nan consoles Yaya on his deathbed, life and death are natural, and after passing away he is posthumously conferred the title Duke Wenxiang, his spirit for the people transforming into an endlessly burning spark.