Sinopsis: In the late Qing and early Republic of China period, there is unrest, bandits and warlords wreaking havoc, and rampant crime. A series of murders breaks out in Jiuhe Town, a small county in the northwest of China, in which many died in strange and mysterious ways, as if they were harmed by evil forces. This causes panic in the town and puts every one in danger. So the county’s female constables, Sangeng and Qixi, are ordered to conduct in-depth investigations. Surprisingly, red phosphorus powder, commonly known as Gumizi, is found on the corpses and at the scene of the murder. This powder is commonly used by magicians in the martial world as a prop. To seek clues, the two of them invites the Western magician Xin Shisi, who is deeply hidden in the mountains, to assist in solving the case. They unexpectedly get acquainted with the mysterious little magician Xiaobai, who was secretly investigating the case alone. The joint investigation gradually reveals that the mysterious murder case seems to be related to a mysterious organization, and leads to an old grudge about the evil organization "Lao Ke’er" that was destroyed 20 years ago. The case becomes increasingly complex and confusing, in which Lao Ke’er revives and several people involved in the investigation also experience accidents successively. The originally small and peaceful county becomes shrouded in a terrifying atmosphere created by a strange and chaotic spirit.