A series of gruesome mruders takes the city by storm. Each crime is elaborately staged and executed with high level of skillfulness. All murders have something in common: The victims are subjects of recent media controversy when their apathetic, selfish wrongdoings cause the death of others. The way they were executed also bears resemblance to certain details of their misdemeanor. The media immediately labels it an act of vigilante justice and the whole town becomes enthralled with the serial killer. People are frantic to see his next act of gigilantism.
Police detective Nam(Liu Shishi), who's been assigned to the case, is practically running out of leads and time. She enlists the help of ex-cop/forensic expert Mu(Deng Chao), who quickly discovers invisible traces of evidence left at the crime scenes. Togetherm they are wasting no time in hunting the killer before the next murder occurs.
At the same time, the serial killer (Ethan Juan) has chosen his next victim. He is plotting a live streaming of the execution for people to decide on the fate of the victim. Seeing himself as the guardian of the city, he believes true justice can only be served by transferring power from the law enforcement and giving it back to the people.