While gathering mushrooms in Eagle Cave on Puying Mountain, Wang Gouzi, from Pingpo Village in Yangbi County, discovers the body of Ma San, an antique dealer. Detective Captain Lu Zheng leads the investigation. A piece of Yi silver jewelry engraved with an eagle at the scene connects the case to two old mysteries: the theft of a malachite Yi plaque from the village twenty years ago and the disappearance of Qu, the old man who guarded it. Lu Zheng meets Qu Mei, the old man’s granddaughter, and the two join forces to investigate. Wang Gouzi volunteers to help clear his name, and along the way, single mother Sang Xing comes to his rescue. The two develop feelings for each other. The clues gradually point to Shuan Laogui and his son. On their third exploration of Eagle Cave, the group finds Qu’s diary, which reveals that Shuan Laogui and Ma San conspired to steal the plaque and imprison the old man. Ma San was killed by Shuan Xiaohu when he demanded the plaque. Lu Zheng and his team capture the killer and recover the remains of the old man, who has since died, then give him a Yi funeral. After the case is solved, Lu Zheng and Qu Mei become a couple, and he transfers to the village to protect the Yi community. Wang Gouzi wins Sang Xing’s heart with his courage, then opens a mushroom business that helps the villagers prosper. Qu Mei establishes an Yi embroidery cooperative to preserve the culture, and Pingpo Village becomes a model village by developing tourism around its natural beauty and Yi traditions. One day, Wang Gouzi explores Eagle Cave again and finds a strange stone carved with symbols resembling those on the Yi plaque, leaving a new mystery buried in Puying Mountain.
