罗杰（加里·格兰特 Cary Grant 饰）是个平凡的广告商人，最近却莫名其妙的惹了一身的麻烦——他被别人错认成一名叫“凯普林”的人，还人灌醉放进车中，意图造成车毁人亡，命大的罗杰却顺利逃过这一劫这个离奇的经历让罗杰又后怕又好奇，为了证明自己的清白，他非要找出真正的“凯普林”不可。 噩运在纠缠罗杰。他一路设法摆脱追杀，一边千里追踪凯普林的线索。他跳上了一趟开往芝加哥的列车，车上巧遇娇娃坎多（爱娃·玛丽·森特 Eva Marie Saint 饰），愿意助他一臂之力。眼看就快可以约见凯普林，事情却又起了波澜——他不但没有见到凯普林，还随之陷入了又一场危机当中。真相越来越扑朔迷离，拉什莫山的总统雕像，也成了一场生死搏斗的大舞台。
美国华盛顿特区，新一轮总统大选前两周一桩耸人听闻的总统骚扰未成年少女的性丑闻事件，就在这切要关头被披露曝光，闹得沸沸扬扬。加上新闻媒体的大肆炒作，总统谋求连任的机会简直微乎其微。为了平息这场风波，总统紧急召见了老谋深算的政治顾问康拉德·布里恩博士（罗伯特·德尼罗 Robert De Niro 饰）。善于操纵公众舆论导向的布里恩，在紧要关头很快献出一条“妙计”。为了转移公众对性骚扰事件的注意力，布里恩凭空捏造出一场子虚乌有的爱国战争“阿尔巴尼亚战争”。为了让这场虚构出来的战争真实可信，布里恩专程拜访了大名鼎鼎的好莱坞著名制片人斯坦利·莫斯（达斯汀·霍夫曼 Dustin Hoffman 饰）。在他们“天衣无缝”的导演之下，公众果然信以为真，倍加关注。然而，这场所谓的爱国战争不久便破绽百出，不攻自破。
A romantic and funny love story with a tragic end. In Paris a young Hungarian artist (Monpti) and a girl (Anne-Claire) meet and fall in love. But just when she is prepared to give herself to him she finds a pair of lady's pants in his room. He is perfectly innocent but the reason why the pants are there is as humouristic as incredible. So when he tells the truth she gets very angry though she was prepared to "forgive" his "side step". Another pattern is much more serious. Anne-Claire fears that Monpti would have no interest in her if she told that she is a nobody. So she builds up a story of being a rich girl with a private chauffeur. She even takes Monpti to a family church funeral and points out all her relatives, even telling which ones are not on speaking terms. When he finally exposes her lies a violent explosion results. She runs away in despair and is overrun by a car. At the hospital their love returns. But she will die after a few days. - In the background of many scenes we have seen the couple who overrun Anne-Claire, and their shallow emotions were recurrently contrasted with the genuine love of the young couple.