It quickly becomes clear that Sarah hasn’t recovered from her breakdown and is still plagued by hallucinations. Now, she finds herself fighting for her life as well as her sanity. And as if that wasn’t bad enough, she becomes convinced that something nasty is down there with them. Turns out the girls have wandered into the territory of cave-dwelling creatures that has evolved to suit their dark humble abode.

Primarily shot in Scotland and in Britain's Pinewood studio, The Descent takes its own sweet time with an air of menace. Somewhere around the halfway point, Marshall switches tactics as The Descent downshifts from down-to-earth anxieties to full-on flesh kills. The movie's thrill sequences are nasty and suspenseful, though once the creatures start to attack, the scenes do get repetitive. And while the subterranean setting is conducive to horror, Marshall grinds every last wince out of it.

Marshall makes good use of his claustrophobic setting, heightening the atmosphere by having his scenes dimly lit by torches or green glow-sticks; he also makes good use of a video-camera’s night-vision feature to provide the film with one of its monster shocks, indulging in bit of visual-reference, a-la Aliens and Carrie homage.

The actresses are just fine, especially Mendoza and Reid, but it's hard to distinguish the women from one another, impacted by the poorly lit action sequences. Also, there’s no hint of humour whatsoever throughout the film, which adds oddly to the intensity of the atmosphere. Meanwhile, David Julyan's score moves from the lush pastoral strains of the outdoor scenes to the bellowing underground alarums and honking horns of hell. - B.J.