女教师萨曼莎（吉娜·戴维斯 Geena Davis 饰）和8岁的女儿一起在宁静的小镇里过着安逸的生活，一切都令她感到十分满意，除了她曾经失去过部分记忆这一点。在一次车祸中，她失去的记忆开始复苏，而脑中出现的一些零碎片段让她对自己曾经的身份产生了怀疑。 通过私家侦探米奇（塞缪尔·杰克逊 Samuel L. Jackson 饰）的帮助，萨曼莎得知自己竟是一名联邦调查局的特工，而在调查局里，一个无意中得知了老板秘密的特工是不受欢迎的。萨曼莎仍然健在的消息不胫而走，她能够感觉到，一些非常残暴的恐怖分子正在渐渐接近她和她的女儿，他们的目的只有一个，那就是将她除之而后快。
Samantha Caine, suburban homemaker, is the ideal mom to her 8 year old daughter Caitlin. She lives in Honesdale, PA, has a job teaching school and makes the best Rice Krispie treats in town. But when she receives a bump on her head, she begins to remember small parts of her previous life as a lethal, top-secret agent. Her old chums in the Chapter are now out to kill her so she enlists the help of a cheap detective named Mitch. As Samantha remembers more and more of her previous life, she becomes deadlier and more resourceful. Both Mitch and Charly proceed to do the killing thing, the bleeding thing and the shooting thing.
