The Devil's Mouth

Six college friends on a spring break trip to Thailand decide to explore a remote cave system known as the Devil's Mouth. What starts as an adventurous trek through crystalline waters becomes a fight for survival when a flash flood seals their exit, trapping them inside the flooded labyrinth. Director Jeff Wadlow (Fantasy Island, Truth or Dare) orchestrates a claustrophobic horror-thriller that pits the group against a bull shark that stalks the dark, submerged passages. The ensemble cast includes Kathryn Newton as Charlie, Lana Condor as Kate, Gavin Casalegno as Greg, Nico Hiraga, Tommi Rose, and Tayme Thapthimthong.

The screenplay, originally titled Apex, was written by Aja Gabel and Myung Joh Wesner and landed on the 2019 Hollywood Black List of most-liked unproduced scripts. Wadlow later revised the script to sharpen the survival horror elements. The film was shot entirely on location in Thailand over eight weeks, with principal photography wrapping in September 2025. Produced by Basil Iwanyk and Erica Lee of Thunder Road Films, the movie is a co-production between Amazon MGM Studios and Lionsgate, set for a streaming release on Amazon Prime Video.

Rated PG-13, the film emphasizes tension and psychological dread over graphic gore, drawing on the real-world dangers of cave diving and shark behavior. The title refers to a tidal trap, a cave that fills and empties with ocean cycles, which becomes a ticking clock for the trapped characters. With a runtime of approximately 100 minutes, The Devil's Mouth joins the recent wave of shark horror that includes Under Paris and 47 Meters Down, but distinguishes itself by setting the action entirely in an enclosed underwater cave system. [edit]

Charlie and Kate have been friends since freshman year, but a romantic history they never fully resolved hangs between them. When their group of six, including Greg, James, Adrienne, and a sixth friend, arrives in Thailand for a final spring break before graduation, they are determined to make it unforgettable. Greg, the most adventurous of the bunch, convinces the others to visit a local landmark: a submerged cave network called the Devil's Mouth, known for its turquoise pools and dangerous currents.

The group hires a local guide who warns them about the cave's unpredictable tides and advises them to stay within the marked safe zones. Ignoring the caution, they venture deeper into the system, marveling at the otherworldly rock formations and bioluminescent algae. The water is warm and clear, and for a while it feels like paradise. Then a low rumble echoes through the cavern. Within seconds, the exit passage collapses under the force of a flash flood, sealing them inside. The water level rises rapidly, forcing them to swim deeper into the cave in search of higher ground.

As the initial panic subsides, the group takes stock of their situation. They have limited flashlights, no phone signal, and a dwindling supply of oxygen if they need to dive through submerged tunnels. Greg tries to maintain morale, but cracks appear. James jokes nervously, Adrienne points out the flaws in every plan, and Charlie and Kate exchange tense silences. The first attack comes without warning. A dark shape moves through the water. One of the group is pulled under and disappears. When they surface, there is only blood.

The survivors realize they are not alone. A bull shark, adapted to both salt and fresh water, has made the cave its territory. The predator is fast, silent, and methodical. It uses the cave's narrow passages to ambush its prey. The group must navigate a labyrinth where every submerged tunnel could lead to safety or to the shark's jaws. They find a small air pocket where they can rest, but the water continues to rise as the tide comes in. Their only hope is to find an exit before the cave fully floods.

Trust begins to fray. Greg insists on a plan to swim through a long underwater passage he spotted on the way in, but Adrienne argues it is too risky. Charlie discovers that Kate has been hiding a small underwater flashlight with a stronger beam, a detail Kate withheld to avoid arguments over who would carry it. The revelation deepens the rift between them. James, injured in the initial collapse, slows the group down. They debate whether to leave him behind. The moral calculus of survival becomes brutal.

As the tide rises, the shark becomes more aggressive. It attacks again, claiming another victim. The survivors are forced to split up, with Charlie and Kate taking one route and Greg and Adrienne another. Each group faces its own horrors: dead ends, tight squeezes, and the constant threat of the shark appearing from the darkness. Charlie and Kate must work together despite their history, navigating a flooded chamber where the only exit is a narrow crack at the bottom, barely wide enough to squeeze through. The water is pitch black. They have one flashlight between them.[edit]