One of the scariest movies I have EVER seen!

Rating: 10/10 (25 May 2006)

After a horrific family car crash, Sarah (Macdonald) is finally ready to start her life over again with her four best friends (Mendoza, Reid, Buring and Mulder), plus one new one (No one). Their traditional extreme holiday this time involves cave exploration, but a stupid decision and a couple of accidents leave them lost underground. They spot signs that they're not the first spelunkers to pass this way. And also that they may not be alone in the dark.
The closed-in space makes a superb horror movie set--we can barely stand to watch them squirm through the tiny gaps, traverse Lord of the Rings-size chasms, and cope with things that go bump in the dark. It helps that Marshall spends just the right amount of time setting up the situation before the women head into the cave. They're all well played, but only Macdonald, Mendoza and No one are able to add any real definition; the other three feel completely interchangeable.
To make up for this, Marshall lays on the chills early on, with the terrible car crash, dream sequences, jumps and false starts, sudden birds and bats lunging at the camera. And most of all, an obvious willingness to get seriously grisly. By the time the women see strange marks on the cave walls, we're already completely unnerved. Then it gets increasingly blood-soaked and primal. There are some problems, mostly in the difficulty we have in meaningfully connecting with any of the characters, and it's not easy to keep up with the chaotic, poorly lit action sequences.
But Marshall is clearly having fun here, and he effectively assembles all of the elements to gross us out and scare us half to death. References abound, most obviously The Blair Witch Project and Carrie. While the final turn of events (well, the final few turns of events) are seriously unhinged--and surprisingly emotional for this genre.