故事发生在一个湿气蒙蒙的十月日子里，广告总监查尔斯（克里夫·欧文饰）错过了他原本要搭乘的列车。然而，在下一班列车上，因为一张车票，他与金融投资顾问露辛达（詹妮弗·安妮斯顿饰）相遇了。两人彼此留下了深刻的印象。此时，查尔斯的女儿患上了糖尿病，他需要花更多时间照顾她。与此同时，他在事业上遭遇了挫折，而妻子又忙于工作，无法给予他情感上的支持。在接下来的日子里，查尔斯和露辛达频繁见面，两个已婚的人逐渐产生了更深的联系。最终，他们在一次约会后来到了宾馆，那里成为他们逾越婚姻界限的地方。

这段不道德的感情迅速突破了禁锢，他们沉浸在越轨带来的快感中。就在这时，愤怒的敲门声打破了一切。一个名叫拉罗克（文森特·卡索饰）的陌生人闯入了房间，他手持黑洞洞的枪口指向这对越轨男女。这段出轨的感情转变为一场危险的噩梦，伴随着暴力和无法预见的伤害。查尔斯的生活被欺诈和犯罪填满，他被妻子怀疑，无法向警察求助。现在，他只能依靠两个人的力量，夺回曾经宁静的生活。

On a humid October day, advertising director Charles (Clive Owen) Missed the train he was supposed to be on. However, on the next train, because of a ticket, he met Lucinda (Jennifer Aniston), a financial investment consultant. The two made a huge impression on each other. At this point, Charles' daughter became diabetic and he needed to spend more time caring for her. At the same time, he suffered setbacks in his career, and his wife was too busy with work to give him emotional support. In the days that followed, Charles and Lucinda saw each other frequently, and the two married people gradually developed a deeper bond. Eventually, they ended up at the hotel after a date, and it became the place where they crossed the boundaries of their marriage.

This immoral relationship quickly broke through the confinement, and they were immersed in the deviant zone In the pleasure of coming. At this moment, an angry knock on the door broke everything. A stranger named Laroque (Vincent Cassel) broke into the room, and he pointed a black muzzle at the deviant couple. The affair turns into a dangerous nightmare, complete with violence and unforeseen injuries. Charles' life is filled with fraud and crime, he is suspicious of his wife and unable to turn to the police. Now, he can only rely on the strength of two people to regain his once peaceful life.