Director:
(played by Wu Yijiang) writes an article to expose the shady story of the police industry / and is regarded as a thorn in the side of Detective Zhang Yaozu (played by Wu Yijiang). Zhang Yaozu framed Cheng An for possessing drugs and sent him to jail. He also defiled Cheng's girlfriend Xiaoci (played by Zhang Wenci). In prison / Cheng An was regarded as a "sheep" outside of gang members. Although he was cared for by Sheephead Ji Mo (played by Ng Meng-tat) / he was also insulted by the bosses. Cheng An relied on his integrity and knowledge to advocate for the rights of prisoners / and gradually gained the respect of the bosses / and his life in prison improved. Soon the guard "Inhumane" (played by Lin Guobin) killed the prisoner "Three Legs" (played by Xu Jinjiang). Cheng An borrowed friends from the press to avenge the three legs. Xiao Ci relied on the power of another detective to put Zhang Yaozu in prison. Zhang Yaozu / who became a prisoner / planned to retaliate against Cheng An in prison. The duel between the two was inevitable...
六十年代的香港警界贪污成风，导致黑狱重重，《正报》记者程安（梁朝伟 饰）撰文揭露警界黑幕，被探长张耀祖（吴毅将 饰）视为眼中钉。张耀祖陷害程安藏毒，使其入狱，更将程的女友小慈（张文慈 饰）玷污。程安在狱中作为帮派人士之外的“羊”，虽有羊头飞机木（吴孟达 饰）看顾，也受尽大佬们侮辱。程安凭借正气与知识为犯人声张权利，逐渐获得大佬们尊重，狱中生活有所好转。不久看守“无人性”（林国斌 饰）将犯人“三只脚
