『日產亂(luan)碼一區區』介紹:解放前(qian)的(de)舊上海,各方(fang)勢(shi)(shi)力(li)匯集于此,此消(xiao)彼長(chang),橫行霸(ba)道。青龍(long)(long)幫(bang)與麒(qi)麟幫(bang)兩大黑道勢(shi)(shi)力(li)為爭霸(ba)主地(di)位經常(chang)大打出(chu)手(shou)(shou)(shou)(shou),血濺(jian)街(jie)頭(tou)。某天(tian)(tian),青龍(long)(long)幫(bang)三名成員(yuan)(yuan)橫尸街(jie)頭(tou),醫科大學女(nv)教授于勝男(齊芳飾(shi))以及(ji)巡捕房“老虎探(tan)長(chang)”鐘朗(lang)(lang)(鐘漢良飾(shi))、實習探(tan)員(yuan)(yuan)韓非(釋(shi)小龍(long)(long)飾(shi))相繼趕到現(xian)(xian)場(chang)調查(cha)。結果發現(xian)(xian)死者均(jun)系(xi)槍法極準的(de)高手(shou)(shou)(shou)(shou)用“達姆彈”射殺,鐘朗(lang)(lang)斷定兇手(shou)(shou)(shou)(shou)是(shi)有著(zhu)軍(jun)方(fang)背景的(de)狙擊手(shou)(shou)(shou)(shou)所為。與此同時自稱(cheng)北(bei)伐軍(jun)獨立(li)團老兵(bing)的(de)劉天(tian)(tian)河出(chu)現(xian)(xian)在他們(men)面(mian)前(qian),并向(xiang)眾人(ren)透露兇手(shou)(shou)(shou)(shou)的(de)真正(zheng)身(shen)份。另(ling)一方(fang)面(mian),青龍(long)(long)幫(bang)老大認定手(shou)(shou)(shou)(shou)下是(shi)為麒(qi)麟幫(bang)所害,雙方(fang)劍拔(ba)弩張,上海灘即將(jiang)掀起一場(chang)史無前(qian)例的(de)血雨腥風(feng)。為了(le)避免更大規模(mo)的(de)械斗(dou),鐘朗(lang)(lang)必(bi)須爭分奪秒找到真兇……