这是一部谍中谍式的电影，不过主角换成了狙击手。美国退役优秀狙击手鲍勃（马克•沃尔伯格 Mark Wahlberg 饰）正在阿肯色州享受退役后的休闲时光，不料，平地生波，他的前上司前来拜访他，希望他能接受一项新的任务――在总统街头演讲那天充当隐形狙击手暗中保护总统。虽然十万分不情愿，但禁不住上司的游说，鲍勃最终答应了。总统演讲那天，鲍勃正在仔细观察着四周情况时，突然会场遭到枪手袭击，总统身边的衣索比亚主教被杀。鲍勃被当成暗杀者遭遇警方追捕。心知成了替罪羔羊，鲍勃在身中两枪的情况下奋力逃走了。鲍勃此时唯一的出路就是找出幕后的真凶，为自己洗刷罪名。Bob Lee Swagger, one of the world's great marksmen and the son of a Congressional Medal of Honoree, is a loner living in the Rockies. He's left the military, having been hung out to dry in a secret Ethiopian mission a few years before, when he's recruited by a colonel to help find a way that the President of the US might be assassinated in one of three cities in the next two weeks. He does his work, but the shot is fired notwithstanding and Bob Lee is quickly the fall guy: wounded and hunted by thousands, he goes to ground and, aided by two unlikely allies, searches for the truth and for those who double-crossed him. All roads lead back to Ethiopia.