Just how scary can grass be? Ask Stephen King and Joe Hill, who crafted an immensely disturbing tale of terror called In the Tall Grass. Then ask director Vincenzo Natali, who has taken King and Hill’s story and worked it into an off-the-wall crazy adaptation that mostly captures the madness of the story…but not quite. Just when you think Natali will fully embrace the shocking twists of the source material, the filmmaker takes the easy way out, resulting in something that’s both horrifying but also oddly muted.

Just what the hell is it with Stephen King and billowing, overgrown fields? His Children of the Corn confirmed how creepy cornstalks could be, and now In the Tall Grass – based on a story by King and son Joe Hill – turns something as harmless as uncut grass into a nightmare. Without spoiling too much, let’s just say that King and Hill’s Tall Grass is one of the most disturbing stories you’ll ever read – a fact which can’t help but hype up Vincenzo Natali’s new film adaptation headed to Netflix after a premiere at Fantastic Fest. Natali embraces many of the chilling moments of the story, but he can never entirely commit to the nastiness. Ultimately, it’s best to separate the film from the novella.

Brother and sister Becky (Laysla De Oliveira) and Cal (Avery Whitted) are cruising down a backcountry road on their way to California. Becky is very pregnant, and the baby’s father Travis (Harrison Gilbertson) is out of the picture. The drive couldn’t seem more harmless – until the siblings have to pull off the road so Becky can engage in some puke-filled morning sickness. Their car happens to stop by a spooky, abandoned church, which stands before a vast, sprawling field of billowing grass. Before the two can get back on the road, they hear the voice of Tobin (Will Buie Jr.), a young boy calling for help from within all of that tall grass.

Seems like a simple solution, right? Just pop into the grass, find the lost kid, and save the day? But things aren’t so simple. Once Becky and Cal are in that grass, time and space begin to bend, twist, and behave in ways that defy logic. Voices come from every direction, and the place someone id currently standing one second won’t be the same spot they’re standing in a second later. And Tobin isn’t the only person lost in that grass. There’s also Tobin’s dad Cal (Patrick Wilson), who seems helpful at first – but slowly grows more sinister, descending into full-blown Jack Torrence mode.

Chaos soon reigns, with nothing ever quite making sense as the grass – and an ominous black stone at the center of the field – twists and warps the minds of our protagonists. De Oliveria and Whitted are well-matched as the endangered siblings, but it’s Wilson who steals the show, clearly reveling in his meaty, often hammy performance. Anytime In the Tall Grass becomes in danger of dragging, Wilson pops-in to liven things up.

Natali’s direction zeroes in on the landscape – shot after shot of billowing blades of grass, and imagery that sharply turns from lush green to blood red. The film is often visually stunning, and when things grow more and more dire, Natali is able to find beauty within brutality. Still, In the Tall Grass can never fully commit to the horror lurking within. Even if you’ve never read the short story, you can sense the cold, stark, unflinching horror lurking beneath what Natali has conjured up. And you long for it, too. You want the movie to be darker; meaner; nastier. You want the horror to never let-up.

That’s not to say In the Tall Grass isn’t plenty horrifying. There are moments of extreme brutality within the frames of this film – heads crushed, bodies mangled, bones obliterated. And beneath the body horror is the lingering sense of insanity – the type of cosmic insanity that H.P. Lovecraft made so famous, where nothing is as it seems, and the very act of encountering the horrors within are enough to drive one mad. But In the Tall Grass still comes up short. There’s a horror masterpiece lurking somewhere beneath the blades of grass in this film, but it’s lost in all of that greenery. You’ll be plenty disturbed by what’s in store here, but you’ll also come away wondering how much more horrifying it could’ve been.

/Film Rating: 7 out of 10