Most thrillers need a bad guy. Someone has to be chasing you, hunting you, sabotaging the mission or generally making an already bad situation worse.

Last Breath doesn’t bother with any of that.

There’s no villain here. There doesn’t need to be. Put a man hundreds of feet below the surface of the North Sea, disconnect him from the equipment keeping him alive and suddenly Mother Nature has provided all the conflict you could possibly want.

And the fact that this is based on a true story makes it considerably more unsettling. Last Breath follows saturation divers Chris Lemons, Dave Yuasa and Duncan Allcock, played by Finn Cole, Simu Liu and Woody Harrelson. When something goes catastrophically wrong during a dive, Lemons ends up stranded on the ocean floor while the people above him desperately try to figure out how to get him back.

That’s the movie.

A lot of modern thrillers don’t trust the situation. There has to be another twist, another betrayal, another character with some secret agenda. Eventually you’re watching people fight each other instead of dealing with the thing that made the movie interesting in the first place.

Last Breath understands that being trapped at the bottom of the North Sea is enough.

What makes it even better is that these aren’t ordinary people who wandered into danger and have no idea what they’re doing. These are professionals. Saturation diving is an incredibly specialized job involving equipment and procedures most of us probably didn’t even know existed before watching the movie. The divers live under pressure for extended periods, descend to extraordinary depths and rely on an entire system above them to keep them alive.

So when that system starts failing, the movie doesn’t suddenly turn everyone into an idiot just to create suspense.

They work the problem.

That may not sound as exciting as a car chase, but there’s something very satisfying about watching competent people deal with a situation where the margin for error is essentially nonexistent. It’s one of the reasons movies like Apollo 13work so well. The suspense comes from watching people who know exactly what they’re doing slowly run out of options.

Woody Harrelson is particularly well suited to that kind of movie. He has enough presence that you immediately buy him as somebody who has been doing this for a long time, but Last Breath doesn’t turn him into some larger-than-life action hero. Simu Liu gets to be similarly restrained. These are guys doing an extremely dangerous job who suddenly find themselves dealing with something none of their training can easily fix.

Meanwhile, Finn Cole spends much of the movie in the worst possible place: alone.

The underwater scenes are what really separate Last Breath from a lot of other survival movies. There’s something uniquely unnerving about deep water because almost everything we normally associate with safety disappears. You can’t simply walk away. You can’t breathe. You can barely see. Even when somebody knows exactly where you are, reaching you can still be extraordinarily difficult.

The ocean doesn’t have to chase you. It can just wait.

If you like survival movies, rescue movies or stories about people trying to solve seemingly impossible problems, Last Breath is exactly the kind of thriller I’m always looking for. It doesn’t need a mastermind, a monster or somebody holding a gun.

Sometimes the situation really is scary enough.