南加利福尼亚，高中生布伦丹·弗莱（约瑟夫·戈登-李维特 Joseph Gordon-Levitt 饰）接到前女友艾米丽•考斯特奇（艾米丽·Emilie de Ravin 饰）的电话，分手两个月来她过得并不好，似乎正在面临巨大的磨难。在接下来的两天里，布伦丹四处寻找艾米丽，最终看到的却是她的尸体。为了弄清艾米丽死亡背后的真相，布伦丹执着地展开调查。他寻找任何可能与艾米丽有关的人与事，从而卷入巨大的黑暗漩涡之中……...
In the midst of summer, Alex, a successful influencer, invites a few friends to her small isolated country house. One evening, after streaming a live video, they are visited by a particularly persistent stalker - The begining of a dreadful night they'll never forget....
