Ximena, a successful psychiatrist, receives an unexpected visit from her elder daughter, Tamara, after a long time without seeing her. Her stay at a spiritual community has distanced and completely changed her. While Tamara takes refuge in her mother's home, an investigation is opened into the disappearance of Tamara's newborn son in strange circumstances within the sect to which she belongs. Both the law and Ximena will try to find out what has happened to the missing baby.

《陌生人》是一部超自然惊悚片，以倒叙的方式讲述故事，背景设在加拿大西北部。片中主角马丁是一个神秘的人物，他来到一个安静的小镇，想要杀死他的妻子安娜，安娜患有一种非常危险的疾病，她像马丁一样，沉迷于吸食人血。然而，当他到达镇上时，他发现安娜已经死了几年，并决定自杀以彻底根除这种危险的疾病，但在他自杀之前，马丁遭到腐败警察中尉的儿子迦勒率领的三名当地暴徒的残酷袭击，这一事件突然引发了一场雪球，将社区陷入一场大屠杀。