Every few years, a horror movie comes along that makes me immediately want to revisit The Descent. Not because it meaningfully builds on what Neil Marshall accomplished, but because it serves as a reminder of just how difficult it is to make cave horror genuinely terrifying. Claustrophobia, darkness, dwindling oxygen, and the inability to know what’s around the next corner should be enough to sustain ninety minutes of tension on their own. The Devil’s Mouth certainly understands those ingredients exist. Unfortunately, it mistakes simply having them for knowing what to do with them.
The setup follows five friends who travel to Thailand to explore the infamous Devil’s Mouth cave system before adulthood inevitably sends them in different directions. What begins as one final adventure quickly becomes a desperate fight for survival once they realize something is stalking them beneath the water. Trapped underground, every wrong turn becomes increasingly dangerous as panic sets in and the group slowly begins turning on one another.
To the film’s credit, there is at least one sequence that genuinely works. One of the opening scenes involving a swarm of jellyfish creates an image I honestly can’t remember seeing in a horror movie before. The setup leading into it is admittedly pretty ridiculous as the friends forget one of their own while she snorkels in the ocean and they play drunken card games on the yacht, but once those translucent bodies begin surrounding Sara (Kathryn Newton), the film for a fleeting second taps into the kind of primal fear it should’ve mined the rest of the way. It’s visually memorable, genuinely unsettling, and one of the few moments where director Jeff Wadlow seems interested in crafting suspense in new ways rather than simply waiting for the next creature attack.
Kathryn Newton does what she can with the material. She’s a consistently engaging screen presence, even when the movies surrounding her don’t deserve it. Looking at her recent horror résumé has become a bit of a roller coaster. Earlier this year, she was one of the best parts of Ready or Not 2: Here I Come, while projects like 2024’s Lisa Frankenstein and now The Devil’s Mouth feel well beneath what she’s capable of. Even Paranormal Activity 4, a film that plenty of people dismissed, has horror sequences that linger in my memory far more than anything here. Newton remains perfectly watchable throughout, but there’s only so much an actor can do when they’re surrounded by characters who barely resemble real people.
Somebody at MGM really needs to be reminded that The Descent already exists, because nearly every scare here feels like a lesser imitation of something that film accomplished with considerably more craft. The cave environments never become nearly as oppressive, the monster encounters are painfully formulaic, and the reliance on digital effects continually undermines whatever atmosphere the film manages to build.
More importantly, the script gives you absolutely no reason to care about anyone trapped inside these caves. Outside of Newton, I didn’t recognize any of the cast going in, and by the time the credits rolled I wasn’t particularly interested in seeing any of them again. Horror has never required deeply complex characters to be effective, but it does require people who behave with at least some recognizable level of common sense. The Devil’s Mouth repeatedly asks its characters to make decisions so bewilderingly foolish that whatever tension the premise naturally generates quickly evaporates.
Jeff Wadlow’s career has always walked a fine line between knowingly campy and simply too campy for my tastes. I wasn’t particularly fond of Truth or Dare or Imaginary, though I know both films have their defenders/admirers. Maybe The Devil’s Mouth will eventually find a similar audience, but the decision to send it straight to streaming already feels fairly telling.
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Aside from one effective jellyfish sequence and another committed Kathryn Newton performance, The Devil’s Mouth is content recycling cave horror clichés without bringing much personality of its own. It’s too formulaic to stand out, too underwritten to generate real emotional investment, and too derivative to justify revisiting over the films that clearly inspired it. A year from now, I doubt many people will still be talking about it. Ten years from now, I’d be surprised if anyone remembers it existed.
Score: 3/10
The Devil’s Mouth (2026)
- Cast: Kathryn Newton, Lana Condor, Nico Hiraga, Gavin Casalegno
- Director: Jeff Wadlow
- Genre: Horror, Thriller
- Runtime: 106 minutes
- Rated: PG-13
- Release Date: July 29, 2026
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