时空的转换,现在与未来的穿梭,都在杰克(亚德里安·布洛迪 Adrien Brody 饰)身上神奇的发生着。他本来是一个参与过海湾战争的美国军人。意外中弹令他丧失了记忆,成为一个失忆者。继而更倒霉的是,他被警方认作杀人疑犯拉回审讯。因为判定为精神疾病,杰克免于坐牢,只是被带到精神病院,作为某项科学实验的样品。 医生为杰克穿上了紧身衣物,把他放进停尸间。这里黑暗冰冷,只剩下零散的记忆碎片陪伴杰克。碎片中有着他将来的模样,有着一个心爱的叫杰基(凯拉·奈特利 Keira Knightley饰)的女子,更有着自己快要死去的讯息。在记忆中看到将来的杰克,在一线希望中寻找着通往生机的钥匙。The film centers on a wounded Gulf war veteran who returns to his native Vermont suffering from bouts of amnesia. He is hitching and gets picked up by a stranger, things go pear shaped when a cop pulls them over and is murdered by the stranger. The vet. is wrongly accused of killing the cop and lands up in an asylum. A quack doctor prescribes a course of experimental therapy, restraining him in a heavy duty straight jacket-like device, and locks him away in a body drawer of the basement morgue. During course of his treatment he gets flashbacks and visions of his future , where he can foresee he is to die in four days time. The catch is he doesn't know how. Thus commences the classic race against time.