Adam(杰克·吉伦哈尔 Jake Gyllenhaal 饰)是一所大学的历史系副教授,和女朋友生活在一起,每天上班下班,过着平静的生活。直到一天,他在一部电影里发现了一个长得和他一模一样的演员。他利用互联网找到了该演员的资料,并联系上了他。 和Adam长得一模一样的演员叫Anthony,有一个怀孕的妻子,他一开始只把Adam当成一个疯狂的影迷,直到上网搜索了Adam的资料,终于下决心和Adam见面。 两人约定在一个旅馆见面,Adam见到一个长得和自己一模一样的Anthony,心生恐惧,告知对方此后不要再见便匆匆离开。然而几天后,Anthony却出现在Adam家中,并提出了一个奇怪的要求......Adam Bell is a Toronto area History college professor. He is a rather somber man, largely because he is stuck in a routine, which includes a relationship with his live-in girlfriend, Mary. While watching a rental movie, he spots an actor in a bit part that looks like him. He becomes obsessed with finding out about this double of his. He learns that the actor's stage name is Daniel Saint Claire, whose legal name is Anthony Claire. Claire is a Toronto based actor with only a few on-screen credits, and is married to a woman named Helen who is currently several months pregnant. Adam then becomes obsessed with meeting Claire, who he learns upon first sighting that they look exactly the same, from the facial hair to a scar each has, but Claire who outwardly is more "put together" than Adam. Their lives become intertwined as Claire himself ends up becoming obsessed with Adam, but in a slightly different way.