为弥合濒临破碎的家庭关系，艾黛儿（玛利亚·贝洛 Maria Bello 饰）和女儿莎拉（苏菲·斯塔基 Sophie Stuckey 饰）驱车前往英国威尔士，寻找阔别已久的丈夫詹姆斯（辛恩·比恩 Sean Bean 饰）。威尔士海边的自然风光让原本紧张的家庭关系得到些许缓和，但是厄运却接踵而至。某天，在海边玩耍的莎拉不慎跌落水中。詹姆斯和艾黛儿随即展开营救，然而最终一无所获，莎拉就这样从他们的生活中消失了。沉浸在莫大悲痛之中的艾黛儿接下来经历了一连串匪夷所思的事情，她坚信女儿被困在当地人传说的“黑界”之中。为了救回莎拉，艾黛儿不惜牺牲一切…… 　　本片根据Simon Maginn1997年的畅销惊悚小说《Sheep》改编。While in Wales visiting her husband James, Adèlle tries to fix her relationship with her teenager daughter Sarah. They see a weird memorial without the plate and with the name "Annwyn" marked, and the local Dafydd explains that this would be the place where people go after dying in accordance with the Welsh mythology. Later, Sarah vanishes on the beach and the daughter of the local fanatic shepherd, Ebrill, who died fifty years ago, appears in her place. Adele makes a research trying to find how to rescue her daughter from Annway.