1974年,牛津大学教授约瑟夫·考普兰德(杰瑞德·哈里斯 Jared Harris 饰)坚信世间存在着用现有科学无法解释的超自然现象,为了证明自己的观点,他集结了布莱恩(山姆·克拉弗林 Sam Claflin 饰)、哈利(Rory Fleck-Byrne 饰)、克莉丝(艾琳·理查兹 Erin Richards 饰)等三名年轻人组成实验小组,对少女简·哈珀(奥利维亚·库克 Olivia Cooke 饰)展开研究。此前在简的身上曾发生过无数匪夷所思的事情,她自称有一个看不见的朋友艾薇搅扰了她的人生,事件影响甚广,连官方都承认简被恶魔附体。约瑟夫信心满满,即使研究经费被撤走,他也执着地要找到致令少女精神失常的原因。 然而他的实验很快跌入了完全看不到尽头的恐怖深谷……In 1974, Oxford professor Joseph Coupland invites introspective lad Brian McNeil to film his experimental treatment of subject Jane Harper, aided by student assistants Krissi Dalton and Harry Abrams. Jane, a young woman with no memory of the past and repeatedly abandoned by foster families, believes herself possessed by a doll named Evey that gives her telekinetic power. Keeping her awake in an isolated house, Prof. Coupland intends that she puts her evil energy into an actual doll, thereafter destroying it to heal Jane. Amidst strange things happening in the house, Brian feels sorry for Jane and, researching her tattoo, learns an evil secret about Jane's past, and of Prof. Coupland's motivation.