根据香格里拉的传说改编，故事描述一支登山队（Aaron Douglas和Paul Campbell主演）前往险峻的喜马拉雅地区寻找一支神秘失踪的探险队，却意外发现大山深处隐藏着传说中的香格里拉。一群嗜血的外星怪兽以此为据点，杀害任何踏入其势力范围的生物。

It's Halloween eve on Shelter Island, and the small town is preparing for a killer storm. But the dark clouds gathering over the island are bringing with them a curse one-hundred years in waiting. As the woods give birth to an ungodly and insatiable creature of fire, bones, and earth, three sisters must scramble to stay alive through the long dark night of the Hollow. For it's not something you can kill. It's only something you can try and survive.

一年前的这个小镇发生一宗凶残的当地女童谋杀案，至今仍然没破案。一年后，一个全身浴血的男孩子在警局出现。警长积克为女童一案耿耿于怀，现在他得面对自己的心魔。他正尽全力去找出这个男孩的真正身份和有可能的被害者。但积克不知道他将会面对非常恐怖的事情。在目出之前，生人得为死者妨受痛苦付出代价。

In 1986, three teens were brutally murdered after knocking on the door of 59 Oakwood Lane. The killer was never found. Over the next forty years, rumours turned to legend, and while few will admit to believing the stories, kids are still warned never knock on the door of 59 Oakwood Lane for fear of what may answer.On this Halloween night, Grace and her friends are going to wish they’d heeded the warnings and never knocked…