Carter (Thomas Jane), a troubled veteran who gets a chance at redemption by protecting a 12 year-old girl from an assassin after she witnesses a murder. Holding a shotgun with a single shell, he engages in physical and psychological warfare in a desperate fight for the girl's life.

安娜怀疑自己与伴侣的感情可能并不像想象中那么真实，为了改善关系，她开始在一家神秘的研究所工作，这里专门负责挑拨或测试那些怨偶间是否真的存在过浪漫的爱情。