因父亲被害,14岁的玛蒂·罗斯(海莉·斯坦菲尔德 Hailee Steinfeld 饰)抵达案发地史密斯堡,作为长女代表家人处理后事。杀死父亲的凶手汤姆·切尼已不知去向,在这枯燥又忙碌的西部小镇上,没人关心杀死异乡人的逃犯何时落网。玛蒂决定自己雇佣警察为父亲报仇,经人介绍,她选择与醉醺醺的警长罗斯特·考波恩(杰夫·布里吉斯 Jeff Bridges 饰)合作,同时,一名来自德克萨斯的骑警拉博夫(马特·达蒙 Matt Damon 饰)亦希望抓获汤姆·切尼,好在德州获得高额悬赏,为了让切尼在本地被正法,玛蒂必须在拉博夫之前抓到杀父仇人。成熟而坚强的玛蒂与罗斯特踏入了保留地,在那里有众多不法之徒,以及暂时逍遥法外的仇人……Following the murder of her father by hired hand Tom Chaney, 14-year-old farm girl Mattie Ross sets out to capture the killer. To aid her, she hires the toughest U.S. marshal she can find, a man with "true grit," Reuben J. "Rooster" Cogburn. Mattie insists on accompanying Cogburn, whose drinking, sloth, and generally reprobate character do not augment her faith in him. Against his wishes, she joins him in his trek into the Indian Nations in search of Chaney. They are joined by Texas Ranger LaBoeuf, who wants Chaney for his own purposes. The unlikely trio find danger and surprises on the journey, and each has his or her "grit" tested.