Ten years ago, a series of corpse mutilation cases occurred in Nancheng. The murderer used precise techniques to cut the victim's body into 21 pieces and discarded them in different corners of the city. Only a fragment of a brass mirror engraved with the "∞" symbol was left at the scene. Interpol captain Lu Chen pursued the case for three years to no avail, and the case became a mystery. He was also forced to leave the crime team due to his excessive paranoia.
Ten years later, new corpses were found in a garbage dump on the edge of the city. The method of dismemberment and the remaining brass mirror fragments were exactly the same as before - the missing murderer "The Man in the Mirror" committed another crime. At this time, Lu Chen was already a decadent archivist, but was forced back into the investigation by his former partner. As the details of the new case intertwined with the old case, he discovered that the murderer's methods were becoming more mature, and seemed to be deliberately guiding him to relive the trauma of ten years ago: the identity of the victim was related to his informant, and the splicing direction of the mirror fragments pointed to his late wife... When Lu Chen tried to piece together the truth, he realized that he had already become a pawn on the murderer's chessboard, and the broken bronze mirror may have reflected a version of himself that he had never faced directly.
