Acting engineer Li Mo accidentally traveled through time in a construction site accident. When he woke up, he found himself in the Yamen of the Ministry of Industry during the reign of Emperor Gaozong of the Tang Dynasty. He became Li Shan, an eighth-rank official. He confirmed through the bronze mirror that he had completely transformed into a different person. He was shocked to find that what was spread out on the table was the repair drawings of Luoyang Palace. Cui Chengqing, the minister of the Ministry of Industry, deliberately made things difficult and demanded that the settlement problem of the palace city's foundation be solved within three days. Li Mo used modern engineering knowledge to propose a solution, which attracted the attention of Du Youming, Minister of Industry. Li Mo encounters Di Renjie, a young official who is patrolling incognito on the streets of Chang'an, and the two hit it off.
