Laughing is judged guilty of murdering gang lord Michael So and is sentenced to life imprisonment. Locked up behind bars, he meets the seemingly benign inmate Fok Tin Yam, a university professor in criminal psychology who is jailed for drug possession. Highly intelligent and manipulative, Fok reveals the power of his mind games by effortlessly subduing the violent prison bully. He also deduces that Laughing is sent to the prison on an undercover mission to find out the rogue cops within the police force. The clues lead him to inmate Chit, a former sergeant from the Narcotics Bureau who has been suffering from a mental disorder. To unlock the critical information from the deranged man, Laughing must get the help of Fok, but this enigmatic figure has an agenda of his own...
| Actor | Role |
|---|---|
 Michael Tse Tin-WahLeung Siu Tong (Laughing Gor) | Leung Siu Tong (Laughing Gor) |
 Francis Ng Chun-YuFok Tin Yam | Fok Tin Yam |
 Chapman To Man-ChatTai Chit | Tai Chit |
 Bosco Wong Chung-ChakSo Sing Pak (Michael) | So Sing Pak (Michael) |
 Kara Hui Ying-HungSa Po Yau | Sa Po Yau |
 Kate Tsui Tsz-ShanYiu Ho Ho (Paris) | Yiu Ho Ho (Paris) |
 Janice Man Wing-SanCarmen | Carmen |
 Liu Kai-ChiCheuk King Chuen | Cheuk King Chuen |
 Evergreen Mak Cheung-ChingLai Sir | Lai Sir |
 Lam SuetKui Chuen | Kui Chuen |
 Jin Au-YeungYeung Lap Ching | Yeung Lap Ching |
 Lau Siu-MingYe Po | Ye Po |
 Rebecca Zhu ChenliMiss Choi | Miss Choi |
 Jacqueline ChanLittle girl | Little girl |
 Chan Tat-KwongNot listed | Not listed |
 Cheung Wing-CheungNot listed | Not listed |
 Ram Chiang Chi-KwongNot listed | Not listed |
 Jin GangNot listed | Not listed |