The story tells about the prosperous Tang Dynasty, when a demon dragon descended from the sky in Qujiang Lake, and the people of Chang'an became bald overnight, which made the sage furious. Wang Xuan, the magistrate of Huanghe County, secretly investigated the case, and a conspiracy to massacre the city emerged, directly endangering the safety of the sage. Wang Xuan went deep into the Dragon King Sect, solved the puzzle of the golden carp, and cleverly identified the plan to massacre the city. In the end, he found out the truth, successfully rescued the sage, and protected the people of Chang'an.