Never Let Go was inspired by the scariest horror movie you've never heard of.

If you’ve seen the trailer, you know that Never Let Go draws inspiration from some horror classics. But according to director Alexandre Aja, the inspiration came from something more unexpected.

There are similar motifs in some of the best horror movies of all time: a trapped family, an iconic cabin in the woods, and all hell breaks loose from there. Never Let Go, directed by Halle Berry, seems to be going for the same thing… except nothing is as it seems.

In the new film, Momma (Berry) protects her two children from the “Evil” lurking outside, except that only she can see it. Her main goal is to keep the two boys alive by making sure they always stay tied to a rope if they go outside, promising to never let go.

Plenty of classic horror films come to mind as potential inspirations—The Cabin in the Woods, or even The Strangers, which started its franchise earlier this year—but according to Aja, the inspiration for Never Let Go came from a horror film that most fans haven’t even heard of.

Speaking to Dexerto, he explained: “I often thought back (while making the film) to the Japanese film Onibaba. It’s, for me, one of the best films ever made.

There is something special about these two women who live in the tall grass, cut off from the world, and who betray each other through this supernatural solar mask that possesses them. It was quite close to the film I was trying to make.

For the uninitiated, Kaneto Shindo’s Onibaba follows a mother and her daughter-in-law who survive by killing soldiers for their possessions. When the mother learns of her son’s death, she creates said mask to scare her daughter-in-law and force her to stay by her side.

The two films share many similarities, particularly in the isolated locations in which the couple’s adventures take place. Both also follow an unbalanced mother who struggles between the supernatural and what may simply be a loss of touch with reality.

For fans of more classic horror, there’s another influence in Never Let Go that you might be able to spot as well.

“In terms of movies, when I first read the script, it reminded me in some ways of the layers and complexity of The Shining. Even though my movie has nothing to do with that.

There is something resonant about using rope to convey the idea of being safe if you stay inside the house…or at least if you stay connected to the house.

Still considered one of the greatest films of all time, Kubrick’s The Shining saw Jack Nicholson and Shelley DuVall at the Overlook Hotel, with Jack Torrance, played by Nicholson, going on a rampage as he begins to experience the supernatural.

While Never Let Go will be released in cinemas on September 20 in the US and September 27 in the UK, Onibaba and The Shining are available on Max and Apple TV+.

You can also check out the best serial killer documentaries, the best horror movies on Prime Video, and the best Neon horror movies while you wait. Also, find new movies streaming this month.