在一场致命的薄雾摧毁了大部分人类之后，一个神秘的组织正试图拯救剩下的人类。

故事围绕着一群人聚集在一座庄严的豪宅里，在过去的大屠杀现场，进行“红书”的仪式。在灵魂的帮助下，他们试图与已故的亲人重新建立联系。

Ida and Albin are a happy couple. They set off to a cabin in the vast Swedish woodlands to have a fun holiday with their friends. But under the floorboards is an evil that waits to be unleashed.