After Lin Yu came down the mountain to Chang'an, he found that there were many unknown evil things hidden behind this bustling capital. First, a young woman disappeared inexplicably at night. Through investigation, Lin Yu found that he was a fox demon who was good at confusing people. In the process of tracking the fox demon, he met Su Yao and Chen Feng. The three of them joined hands. After some twists and turns, they finally found the fox demon's nest, subdued it, and rescued the missing woman.