Synopsis
Liu Yue Ping (Chrissie Chau) reports to the ICAC about a rich 2G Cao Yuen Yuen (Raymond Lam) who bribed officers of the Hong Kong Correctional Services (HKCS) from inside the prison. William Luk (Louis Koo) decides to infiltrate the prison as an inmate to conduct his investigation, while his partner Ching Tak Ming (Kevin Cheng) and Chief Inspector Lau Po Keung (Julian Cheung) back him up from the outside.
Danger springs from all directions inside the prison. A fellow inmate, ex-Superintendent of Police Wong Man Ban (Lam Ka Tung) is anxious to even the score with William Luk for putting him behind bars 5 years ago. The Superintendent of the prison, Sham Kwok Keung (Patrick Tam) is on the take from Cao Yuen Yuen and turns a blind eye to the constant gang fights, one of which landed William Luk in a custodian ward. With the help of a slick cell mate Wong Lam Luk (Louis Cheung), William Luk is determined to complete his mission…