The English horror thriller The Descent has the potential to do for spelunking what Jaws did for swimming in the ocean. And as funny as the word spelunking is, and as dull as the trailers may appear, neither should obscure the fact that The Descent is the best horror film in years. This is the kind of horror film that makes audiences chatter out of fear, it’s the kind of film that makes people get up and leave in the middle. Best of all, this is the kind of film that makes women molest strangers sitting next to them because they just can’t help themselves.

It starts off conventionally enough with Sara (Macdonald) experiencing a traumatic accident that leaves her in the kind of haunted state that so many horror film protagonists seem to require. A year or so after her ordeal, Sara is invited by her friend Juno (Mendoza) to join a group holiday exploring caves in the Tennessee wilderness. All is well until the group finds themselves lost within uncharted caverns. The cast is quite strong with the characters asserting their identities without the benefit of much time or the reliance on stereotypes, and the cavernous setting provides an ideal environment for a horror film—dark, claustrophobic, practically an alien landscape.

So things are not going well, but they get a whole lot worse when the intrepid women discover that they are not alone. I won’t give away too many details about the monsters that play cat and mouse with our group of heroines, but they move quickly through darkness and attack from the shadows without mercy. Like his film’s creatures writer/director Neil Marshall (Dog Soldiers) is pitiless, creating an unrelenting nightmare. The film’s shock points may seem mechanical at times, but they hit with such precision that they’re never numbing as so many bad horror movies often are. While I suspect that most of this was filmed on soundstages, the camera work here is quite remarkable, conveying panic in darkness while keeping the action intelligible. This is clearly the work of gifted director, and with this film Marshall asserts himself as one of the finest genre filmmakers of his generation. Be warned though: This film is not only intense, it’s grisly, and as black-hearted and bleak a film as you’ll see all year. There’s no relief in this one.

—Edward Rholes