Debt-ridden pacifist Richard Fyre is propositioned to return to his abandoned mercenary ways by flamboyant zealot, Priest, to eliminate his international competition in exchange for a clean slate.
前MMA传奇巴顿·詹姆斯早已告别八角笼，以渔夫身份过着拮据的生活，与妻子卢西亚娜、女儿麦迪相依为命。他的弟弟马龙在MMA赛场遭现任冠军泽维尔·格劳恶意重创，重伤入院，还欠下高利贷巨额债务。为救弟弟、守护即将迎来新生命的家庭，巴顿找到曾被他辜负的昔日教练萨米，重新踏上训练之路，准备重返 ONE 冠军赛的八角笼，与残暴的格劳展开对决。
