The Devil's Mouth: Cast, Plot and Review of Prime Video's Shark Thriller (2026)
- The Devil’s Mouth strands five American friends in a flooded Thai cave with a bull shark, and only Sara gets out. Greg, their guide Wat, Adrienne and James all die, and Max is the shark’s last victim; Sara kills it by baiting it into a rock face until the cave collapses on it.
- Kathryn Newton plays Sara and Lana Condor plays Max — and both actors initially thought they should be playing the other part. The director cast them against their usual types on purpose.
- It was written to be set in Mexico. Ten days before the shoot, the studio offered stages and a crew in Bangkok, so the script was rewritten for Thailand — real freshwater caves used by rescue divers for the early scenes, then two flooded tanks on two soundstages standing in for the thirteen caves the script called for.
- Reviews are poor and viewers are harsher than the critics: 35% on Rotten Tomatoes from 37 reviews against a 17% audience score, and 46 on Metacritic from eight critics, checked 4 August 2026.
The Devil’s Mouth arrived on Prime Video on 29 July 2026: an hour and 46 minutes of five college friends discovering that the flooded Thai cave system they booked a tour of has a bull shark in it. It is directed by Jeff Wadlow from a script by Aja Gabel and Myung Joh Wesner, and it stars Kathryn Newton and Lana Condor as best friends whose friendship is the thing the film is actually about.
The shark is the marketing. The engine is which of the two of them is allowed to make decisions.
⚠️ Spoilers from here.
What is The Devil’s Mouth about?
Five friends on a last trip together before adult life separates them, and a guided swim that goes wrong about as badly as a guided swim can.
Sara, Max, James, Adrienne and Greg are in Thailand celebrating the end of college. The trip matters most to Sara: her recently deceased father visited the same caves, so the tour is partly a visit to him. The cave is named for the stalactites and stalagmites at its mouth, which hang and rise in rows that look like teeth — a detail the film is pleased with, and which has nothing to do with what is actually in the water.
Their guide, Wat, offers two routes: an easy green one and a harder red one. Max pushes for red. That choice is the film’s whole architecture in miniature, because Sara is the one who usually gets overruled.
What none of them know is that a recent storm pushed sea water and sea life into the freshwater system. Almost everything that came in died in the fresh water. One thing did not: a bull shark, the species that can move between salt and fresh water, and the one genuinely well-chosen fact in the premise.
What happens in The Devil’s Mouth?
The group loses its way out, then loses its guide, and then loses the ability to agree on anything.
Warning signs stack up before anyone sees a fin. A sea turtle washes ashore with a bite taken out of it. Deep in the caves the group swims through a chamber of dead sea creatures floating in fresh water. Adrienne cuts her leg badly on a rock, and Wat, following his own policy, says the tour ends here. Max refuses to turn back, and the group follows Max.
Then Sara finds a cloud of blood in the water where Ryan, the excursion’s safety diver, used to be, and Wat finds his damaged mask with a shark tooth wedged in it. That is the point at which the film stops being about a holiday. It is also the point at which the group’s argument starts, and it never really stops: Wat wants everyone out immediately, Max wants a plan first, and the shark does not wait for the meeting to finish.
From there the cave does what the title promises. The group is stranded on rock above the waterline with a bleeding injury dripping into it, an animal circling below, and a route out that only their guide fully understands. When the guide is gone, they navigate on his map — or rather they do not, because Sara reads a route off it and Max chooses a different one, which takes them in a circle back to where the shark first found them.
Who dies in The Devil’s Mouth, and how does it end?
Everyone except Sara — and she kills the shark by making herself the bait.
Ryan goes first, before the group even knows what they are dealing with. Greg is the first of the friends: the shark takes him by the legs at the surface and drags him along the rocks in front of everyone rather than pulling him straight under.
Wat has already gone by then: he decided his own experience was a better bet than the group’s bickering and swam out alone, and the shark caught him in a narrow gorge. Adrienne, whose leg has been bleeding into the water since the rocks cut her, slips off the ledge the survivors are sheltering on; the others reach for her and the shark gets there first.
James is the exception — he is not bitten. Squeezing through a narrow underwater passage, he is pinned by rock, and the group has no air tanks. Sara and Max try to share air with him and cannot free him. He tells Max, who is his girlfriend, to keep going, and drowns.
That leaves the two friends the film has been about all along, and a climb to a gap where the tide reaches the sea. Max’s hand is broken and she cannot make it; the plan is that Sara climbs out and brings help. Max panics and tries the climb anyway, and they rope themselves together so Sara can pull her up. The shark takes Max while Sara is hauling her up, and Sara — still roped to her — is dragged deep into the system before she can cut the rope.
Alone, Sara remembers what Wat said about the cave’s loose rock. She positions herself under an unstable section, uses herself as bait, and lets the shark charge her again and again until the impacts bring the roof down on it. Then she finds a second opening, climbs to daylight, and screams — bloodied, on a ledge above the coast, the only one left.
Newton has described that scream as guttural and animalistic — her version of Sara has spent the film being managed and comes out of the cave, in her own word for it, as the apex predator. The script the film was made from was called Apex.
Who’s in The Devil’s Mouth cast?
Kathryn Newton plays Sara and Lana Condor plays Max, with Nico Hiraga, Gavin Casalegno, Tommi Rose and Tayme Thapthimthong around them — two leads cast against the parts audiences expect, and both of them wanted the other’s role.
| Actor | Character | Who they are in the story | |
|---|---|---|---|
| Kathryn Newton | Sara | The quiet one, on the trip partly to follow her late father into the same cave; spends the film being overruled and ends it as the only survivor | @kathrynnewton |
| Lana Condor | Max | Sara’s best friend and the group’s decision-maker, whose insistence on the harder route and on her own way out drives almost every death | @lanacondor |
| Nico Hiraga | James | Max’s boyfriend, and the only one of the dead the shark does not kill — he is pinned in a passage and drowns telling her to keep going | @nicotheduffer |
| Gavin Casalegno | Greg | Adrienne’s boyfriend, afraid of blood, and the first of the friends the shark takes | @gavincasalegno |
| Tommi Rose | Adrienne | Cuts her leg early on, which turns her into the group’s liability and the reason the shark keeps finding them | @tommirose |
| Tayme Thapthimthong | Wat | The cave guide, the only professional in the group, overruled by tourists and then killed after leaving them behind to swim out alone | @taymettt |
| Sahajak Boonthanakit | Captain | Runs the boat that takes the group out before the tour | — |
| Harrison Luna | Ryan | The tour’s safety diver, who Sara talks to before they go in — and the shark’s first victim | — |
The casting story is better than the film’s. Newton and Condor both read the script and concluded they should swap: Newton is used to playing the loud, dynamic one and Sara is an interior part, while Condor’s usual register is the likeable one and Max needs teeth. Wadlow kept them where they were precisely because it forced both of them off their defaults.
Behind the camera: Jeff Wadlow directs, having previously made Truth or Dare, Fantasy Island and Imaginary; James Kniest shot it; Bear McCreary wrote the score; Basil Iwanyk and Erica Lee of Thunder Road produced alongside Wadlow himself, and Lionsgate and Thunder Road made it for Amazon MGM Studios.
Where was The Devil’s Mouth filmed?
In Thailand — Krabi province, Chiang Mai and Bangkok — although the script was originally set in Mexico and was rewritten roughly ten days before the shoot.
The production had been heading for the Dominican Republic when soundstages and a crew came free in Bangkok and the studio asked Wadlow whether he could shoot Thailand for Mexico. Rather than redress the country, he rewrote for it. Thailand’s remoteness improved the premise’s credibility, he has said: a tourist cave system in Mexico is somewhere help reaches quickly, while the equivalent in a remote part of Thailand is not. He has also credited the 2018 Tham Luang cave rescue, in which a boys’ football team was trapped in a flooded Thai cave system, with making the relocated setting credible: a remote Thai system, he has said, put the group somewhere help would not reach quickly.
The shoot then split in two. The early sequences — the group swimming into the system while it is still beautiful — were filmed in real freshwater caves in Thailand, including one that rescue divers use for training. Everything after that is a set: two cave sets on two soundstages — one tank 120 feet by 70 under five feet of water, a second roughly 60 by 70 under fifteen — dressed, re-lit and rotated to stand in for the thirteen caves the script called for. The director has been open that characters sometimes swim off one end of the set and back onto the same set.
Water dictated the rest of the production. With around 85% of the film shot in it, there is no dolly, no steadicam and no handheld work — an underwater camera housing alone weighs about 120 pounds — and the headlamps had to be custom-built so their brightness and angle could be dialled in from the monitor, pointed away from the lens to stop it flaring while still glowing enough to justify the fill the real movie lights were providing. The cast trained for two weeks in breath-holding and treading water and did their own diving, climbing and winch work, including a 35-foot drop into a shallow pool that the production wanted shot on green screen before the director insisted on the real cliff.
Is The Devil’s Mouth worth watching?
Only if the situation is enough for you, because the architecture is a friendship drama and the shark is the delivery mechanism — one location, one animal, six deaths.
Start with the numbers, since they are unusually lopsided. Checked on 4 August 2026, it sits at 35% on Rotten Tomatoes from 37 reviews, average rating 4.7/10, against a 17% audience score from over 100 ratings, average 1.9/5. Metacritic has it at 46 from 8 critics, and Prime Video’s own page shows an IMDb rating of 4.7. Note the direction of that gap: genre films usually score better with audiences than with critics, and this one is the other way round by 18 points.
None of which slowed it down. It went to number one on Prime Video’s global film chart in its first week, taking the top spot off Masters of the Universe, and was charting in around 50 countries — as of 4 August 2026 it was still the service’s most-watched film worldwide. A 35% Tomatometer and a global number one is the whole story of this release in one line.
What the film actually has going for it is structural. It is a friendship drama in a creature-feature costume, and the deaths are organised around that rather than around set pieces: the red route over the green one, refusing to turn back after the injury, ignoring the route Sara reads off the map. Most of the major losses follow a decision Max makes over Sara’s objection — the red route, the refusal to turn back after Adrienne’s injury, the way out she picks over Sara’s reading of Wat’s map — so the body count doubles as an argument about who in a group gets listened to. That is a real design, and it is why the ending — Sara alone, doing the one thing nobody authorised — lands as a conclusion rather than a survival.
The limitation is the same design seen from the other side. Once you notice that the film is sorting the characters by their usefulness to that argument, the shark stops being a threat and becomes a mechanism, and the middle stretch is a sequence of people ending up back in water the film has already established as lethal. One location and one animal give you claustrophobia; they do not give you surprise, and the film has to spend its last act inventing a way for a swimmer to beat a shark that mostly works because the cave is conveniently unstable.
Our verdict: 6/10 — a friendship drama built inside a creature feature, wrapped around a monster it does not need, and with a better idea in its casting than in its plot. That is our read, not a consensus figure.
If you want another 2026 streaming thriller shot in the same country, our The Debt Collector ending explained and cast guide covers Netflix’s Thai action film from the same fortnight.
Where can you watch The Devil’s Mouth?
On Prime Video, globally, since 29 July 2026.
It is an Amazon MGM Studios original, so it is included with a Prime membership rather than sold as a rental, and it runs 1 hour 46 minutes. It went out worldwide on the same day, so it is there in the US and the UK alike, with dubs and subtitles in a long list of languages including an English audio description track.
Watch The Devil’s Mouth on Prime Video
One note if you are searching: some pre-release previews called the two leads Charlie and Kate. Those were earlier versions of the names — in the finished film they are Sara and Max.