During the Republic of China, there was a city called Pingcheng in the south of the Yangtze River. There is a young detective named He Xiyang in the city. He is only twenty-five years old, but he became famous for solving major cases. With the arrival of autumn, the season when all things kill each other, murder cases with the same tactics have appeared in Pingcheng one after another. The dead are all government officials or business celebrities. Mu Silan, the female police detective in charge of the case, turned to He Xiyang for help. As the investigation of the case deepens, the secrets behind it become more confusing; at the same time, two people of similar age gradually develop a love for each other. The suave, wise and calm He Xiyang, the bold, courageous and beautiful Mu Silan, the cold-blooded forensic doctor An Mingyi, the hot-blooded police officer Xu Wanliang, and Bai Xiaosheng Huo Lijun all show their strengths and cooperate with each other to peel off the cocoons layer by layer. In the end, when the truth was revealed, it was a regrettable ending...