儿童临床医学家凯瑟琳•迪恩（珍妮弗•洛佩斯 Jennifer Lopez 饰）供职于一家研究大脑的医疗研究机构，她的任务是通过高技术手段陷入幼年患者的梦境中，治愈她们幼小心灵中的疮疤。 　　警方接到报案，说当地有很多幼女失踪。负责此案的FBI探员（文斯•沃恩 Vince Vaughn 饰）断定，此举为一个连环作案的变态凶手所为。经过调查，警方锁定了犯罪嫌疑人——卡尔•斯塔格（文森特•德奥诺费奥 Vincent D'Onofrio 饰），但是苦于他守口如瓶，无法救出被他囚禁的女孩。这时，警方联系了凯瑟琳，希望她可以通过梦境的方法，潜入犯人的大脑，找到受害者的所在位置。然而，事情远比想象得更加险象环生……Catharine Deane is a psychotherapist who is part of a revolutionary new treatment which allows her mind to literally enter the mind of her patients. Her experience in this method takes an unexpected turn when an FBI agent comes to ask for a desperate favour. They had just tracked down a notorious serial killer, Carl Stargher, whose MO is to abduct women one at a time and place them in a secret area where they are kept for about 40 hours until they are slowly drowned. Unfortunately, the killer has fallen into an irreversible coma which means he cannot confess where he has taken his latest victim before she dies. Now, Catherine Deane must race against time to explore the twisted mind of the killer to get the information she needs, but Stargher's damaged personality poses dangers that threaten to overwhelm her.