清朝乱世，草莽中人张汶祥（姜大卫）、黄纵（陈观泰）与马新贻（狄龙）不打不相识，结拜为异姓兄弟，马新贻被推为大哥，张汶祥做了三弟。马新贻的勃勃野心引来黄纵妻子米兰（井莉）的爱慕眼光，但因力求上进的雄心和道德观念的约束，马新贻没接受米兰的爱，到升任两江总督后，马新贻变得为达目的不择手段，并在道德和感情防线彻底崩溃的情形下占有了米兰，同时设计杀害了粗豪鲁莽一心向他的黄纵。 　　张汶祥查出二哥的真实死因后，一改平日的跳脱灵动，郑重地约为女人舍弃好兄弟的马新贻出来清账。Assassin Chang and his brother Hung meet up with a soldier, Mu. Together, they form a small mountain army, but when Hung's wife arrives, emotions swell, and Mu leaves for the army. After long, Mu summons his friends to join him, but all the while, he has longed for Hung's wife, and tries to have Hung murdered. This treason forces Hung to take up arms against his former comrade.