The setting is 1960s Hong Kong, and righteous reporter Ching On (Tony Leung Chiu-Wai) publishes an article exposing corruption in the police force. Unfortunately, he's framed for drug distribution and confesses to the charges when the corrupt cops threaten his family. Forced to undergo the rigorous hazing rites of all new inmates, On struggles to regain hope and rise above his situation. Meanwhile, On's loyal girlfriend (Pinky Cheung Man-Chi) is terrorized by the cops who put him away, and On faces new challenges, and even finds new allies, while stuck in prison.
| Actor | Role |
|---|---|
 Tony Leung Chiu-waiChing On | Ching On |
 Richard Ng Man-TatPlane | Plane |
 Ben Lam Kwok-BunMiu Yan Sing | Miu Yan Sing |
 Ben Ng Ngai-CheungInsp. Cheung Yiu Jo | Insp. Cheung Yiu Jo |
 Pinky Cheung Man-ChiJess | Jess |
 Elvis Tsui Kam-KongThree-Legs | Three-Legs |
 Lee Siu-KayBrother Nan | Brother Nan |
 Frankie Ng Chi-HungBrother Doggie | Brother Doggie |
 John Ching TungBrother Bill | Brother Bill |
 Raven Choi Yip-SanBrother Wai | Brother Wai |
 Vincent Wan Yeung-MingWan Chi Hoe | Wan Chi Hoe |
 Law Kar-YingGuard | Guard |
 Lee Lik-ChiM.P. | M.P. |
 Peter Lai Bei-DakNot listed | Not listed |
 Wong Shu-TongOn's boss | On's boss |
 Lai SuenNot listed | Not listed |
 Bowie Lau Bo-YinNot listed | Not listed |