In order to benefit the people, the wealthy Shen Fu of the Ming Dynasty paid for the construction of the city wall. Unexpectedly, during the construction process, the river demon rampantly destroyed the city wall under construction, and the people were panicked for a while. To appease the people, the emperor ordered Shen Fu to offer the heirloom pot of treasures to suppress the evil spirits, and was given a three-day deadline to order Shen Fu and Li Han Yang, the left minister of the Ministry of Works, to repair the city wall. The river demon is still going around, and Shen Fu investigates with his companions to discover that there is something else going on. What is the secret behind it? While fighting the monster, how can Shen Fu solve the case within the three-day deadline?