Thirty years ago, his parents were murdered. The true identity and motive of the murderer remain a mystery. Private detective Chen Qiang (played by Aaron Kwok) tracked them down to Malaysia just to find out the cause of his parents' death. However, the memories of the people who had been in contact with his parents were inconsistent, and he was dissuaded from continuing the investigation. During this period, Chen Qiang's home was also broken into. Isolated and helpless, he turned to local private detective Zheng Fengxi (played by Nick Cheung) for help, asking him to help find the background of the people involved and the whereabouts of certain important people. Zheng was currently worried about his brother's affairs, but he could not stand Chen's provocation and resolutely accepted the commission. But from the day he started the investigation, all kinds of dangers followed him. Intertwined with the evil shadows of drugs and desire, the two detectives, whose lives were hanging by a thread, gradually approached the truth of the year...