本片根据美国小说家丹尼斯·勒翰(Dennis Lehane)的同名小说改编。 1954年,联邦警官泰迪(莱昂纳多·迪卡普里奥 Leonardo DiCaprio 饰)和搭档查克(马克·鲁弗洛 Mark Ruffalo 饰)乘船来到波士顿附近的禁闭岛精神病犯监狱调查一桩离奇失踪案。手刃亲生骨肉的女犯蕾切尔(艾米莉·莫迪默 Emily Mortimer 饰)从戒备森严的牢室神秘逃脱,藏匿于孤岛深处。泰迪怀疑监狱的主治精神病医师约翰·考利(本·金斯利 Ben Kingsley 饰)有意隐瞒内情,并向查克透露他上岛的真实目的其实是寻找当年纵火烧死他妻子德洛丽丝(米歇尔·威廉姆斯 Michelle Williams 饰)的管理员,并揭露美国政府利用精神病犯人进行人体科学实验的罪行。但随着调查的逐渐深入,真相却变得越来越扑朔迷离……It's 1954, and up-and-coming U.S. marshal Teddy Daniels is assigned to investigate the disappearance of a patient from Boston's Shutter Island Ashecliffe Hospital. He's been pushing for an assignment on the island for personal reasons, but before long he wonders whether he hasn't been brought there as part of a twisted plot by hospital doctors whose radical treatments range from unethical to illegal to downright sinister. Teddy's shrewd investigating skills soon provide a promising lead, but the hospital refuses him access to records he suspects would break the case wide open. As a hurricane cuts off communication with the mainland, more dangerous criminals "escape" in the confusion, and the puzzling, improbable clues multiply, Teddy begins to doubt everything - his memory, his partner, even his own sanity.