斯蒂芬尼（盖尔•加西亚•贝纳尔 Gael García Bernal 饰）是一个充满奇思妙想和新鲜念头的小伙子，他从墨西哥来到法国，并在亲戚的帮助下找到了这份机械枯燥的办公室工作。斯蒂芬尼喜欢做梦，梦里有着各种奇妙的事情；因为害羞他在女孩面前十分拘谨。这天，斯蒂芬尼搬来了一个新邻居——那个笑容温暖的邻居女孩有着和他一样得名字：斯蒂芬尼(夏洛特•甘斯布 Charlotte Gainsbourg 饰)。斯蒂芬发现她的想象力天赋和自己竟然十分相似。他们用只属于彼此的方式交往着，命运的连结也由此开始。

　　From the Louis Hemon novel "M. Ripois and His Nemesis" about Andre Ripois, a philanderer in pursuit of love and riches from Paris to London. Andre is breaking up with his wife, Catherine, over his attentions to her best friend Patricia. While Catherine is out arranging the divorce, Andre, just to keep in practice, hits on the girl upstairs, Diana and then turns his attention back to Patricia, who he tricks into having dinner at his flat on the pretext that Catherine will be there. When he cannot make any progress with her via his usual tactics, he tries to arouse her pity be telling her of his past. In his early, impoverished days in London, he made love to his boss Anne but her dreadful cooking drove him away. Next came Norah who he picked up on a bus and took to his flat and told her about his make-believe inheritance, but she insisted on marriage first, which was not in his plans. Marcelle, a French woman living in Soho, put him on his feet with money, and he repaid her by stealing fifty pounds and running off. He met the wealthy Catherine at his flat where she came to be tutored in French lessons, and ended up marrying him. But, even at his wedding, he had eyes only for Patricia and, he tells her she is his one true love.

　　26岁的克洛伊（梅拉尼·罗兰 Melanie Laurent 饰）至今单身，她独自一人生活在繁华而又冷漠的巴黎，遇人不淑的她似乎总被令她抓狂的怪人所包围着，过去不堪回首，未来又无从幻想，日子过得乏善可陈。但这一切都在她误拿了一只行李箱的那一天发生了改变。
　　行李箱的主人是一个叫做杰克（贾斯汀·巴萨 Justin Bartha 饰）的男子，30岁，刚刚和女友分手，本以为生命行至低谷的他却幸运的中奖得到了来巴黎旅游的机会，但好运没有持续多久，刚刚到巴黎，他就丢了行李箱，而行李箱之中，装着杰克父亲留给杰克的珍贵的宝物。一只行李箱将这两个失意的男女联系到了一起，行李箱之中的宝物让克洛伊坚信杰克就是她今生等待的那个人，为了找到杰克，她愿付出一切代价。