Detective Chen Jiuchuan

Detective Chen Jiuchuan's partner fell into a crack in the Qinling Mine and left behind a last word: "Its frequency is not seven." Three years later, an unknown corpse with its face completely peeled off appeared in the same mining area, with a black pottery fragment in its mouth. Chen Jiuchuan investigated and found that his body was quietly marked by a silver-gray line. What has been sleeping under the Qinling Mountains for thousands of years has awakened. Twelve point seventy-five Hertz—a frequency inaudible to human ears, but the way the mountain speaks.