The film tells the story of how, in post-war Spain, Narcisa (played by Aria Bedmar), a novice with supernatural powers, arrives at a former convent, now a school for girls, to become a teacher. As the days go by, the strange events and increasingly disturbing situations that torment her will eventually lead her to uncover the terrible web of secrets that surround the convent and haunt its inhabitants.

一盒以万圣节为主题的录像带引发了一系列扭曲而血腥的故事，将“不给糖就捣蛋”的节日变成了一场生存之战。