过去悲惨的经历让青年李锦伦（谭咏麟 饰）的个性慢慢变得扭曲不堪，对社会充满了仇恨。某日，他在误打误撞之下杀了人，负责此案的探长（彭建新 饰）在报纸上公然宣称此案的凶手必定是个弱智的性无能，这让李锦伦感到十分愤怒。

　　探长戴骠（董骠 饰）得知李锦伦正是案件的罪魁祸首，又意外得知他是一个孝子，于是心生一计。戴骠假意追求李锦伦的母亲（邓碧云 饰），李锦伦知道此事必有蹊跷，担心母亲受其利用，便想要杀了戴骠灭口，戴骠一记假死骗过了李锦伦，之后又在他的家中设下了重重计谋，一步一步诱导李锦伦落入了圈套，李锦伦误以为自己杀死了最爱的母亲，崩溃下最终落入法网。

Lee Kam Lun (Alan Tam) is an intelligent but psychologically unstable young man who is very filial and loves his mum(Pik Wan Tang) dearly. Trouble brews when he accidentally killed a junkie one night. His subsequent actions arouse the suspicion of another intelligent Inspector (Bill Tung), who kick start a game of cat and mouse by befriending Lee's mum as he tries to expose Lee as the killer. Director Ronny Yu (Fearless, The Bride With White Hair) gives us an effective and tight psychological thriller with some dark humor and plot twists in one of his earlier directorial effort. Cantopop legend Alan Tam and the late Bill Tung both give outstanding performances playing the two key adversaries. tt0089001