When Hong Kong is rocked by multiple gruesome murders, the police forms a task force to investigate. Jun, once a brilliant detective who suffered a mental breakdown, begins his own investigation. Eventually, the police learn that the murder victims are all suspects of cold cases being rubbed out by a figure known as "The Sleuth". Now, Jun and a detective from the task force are on a race against time to beat the brutal killer at its own game.
| Directing | Wai Ka-fai | Director |
| Writing | Wai Ka-fai | Writer |
| Production | Jason Siu Kim-Chau | Producer |
| Production | Elaine Chu Suk-Yee | Producer |
| Writing | Ray Chan Wai-Ban | Writer |
| Writing | Mak Tin-Shu | Writer |
| Directing | Jack Wong Wai-Leung | Action Director |
| Production | Wai Ka-fai | Producer |
| Directing | Terry Ng Ka-Wai | Assistant Director |
| Directing | Becky Chan | Assistant Director |
| Directing | Carmen Lau | Script Supervisor |
| Camera | Cheng Siu-keung | Director of Photography |
| Crew | Ray Cheung Tai-Wai | Cinematography |
| Crew | Samuel Fu Ka-Yu | Second Unit Cinematographer |
| Camera | Kathy Ip Ka-Sin | Aerial Camera |
| Camera | Jeff Cheung Ka-Kit | Aerial Camera |
| Camera | Egg Wong Chun-Wai | Focus Puller |
| Camera | Chan Lok-Men | Focus Puller |
| Camera | Wong Shing-Chung | Focus Puller |
| Camera | Lau Kin-Tai | Focus Puller |
| Camera | Cheung Wai-Ching | Focus Puller |
| Crew | Chi Shui-Tim | Pyrotechnician |
| Production | Xiaonan Yu | Producer |
| Crew | Chan Chun Fung | Stunts |
