一对热血虔诚的爱尔兰裔兄弟，因自卫杀人而得罪黑帮，警署以正当防卫之名无罪释放。从此之后，二人决定以己之力对抗社会渣滓，购买武器以暴制暴，在朋友洛克（大卫·德拉·洛克David Della Rocco 饰）的帮助下清除犯罪分子。联邦警探保罗·斯迈克（威廉·达福 Willem Dafoe 饰）负责侦破案件，本来毫无头绪；但 在黑帮头子“老爸乔”（卡洛·罗塔 Carlo Rota 饰）雇佣了传奇枪手“公爵”（比利·康诺利 Billy Connolly 饰）对抗麦克马纳斯兄弟之后，情况却发生了意想不到的变化……Two Irish brothers accidentally kill mafia thugs. They turn themselves in and are released as heroes. They then see it as a calling by God and start knocking off mafia gang members one by one. Willem Dafoe plays the detective trying to figure out the killings, but the closer he comes to catching the Irish brothers, the more he thinks the brothers are doing the right thing.