Claustrophobia and bloody mayhem collide in the high-adrenaline horror flick The Descent. Six women (including one who lost her husband and child the year before, and one who harbors a bitter secret) spelunk in an unexplored cavern system that turns out to harbor mysterious, predatory creatures. That sums up the story, but--as with writer-director Neil Marshall's previous low-concept movie, Dog Soldiers--the plot doesn't begin to describe the riveting, stomach-lurching thrills this movie provides. The script affords the relatively unknown cast (led by Shauna Macdonald and Natalie Mendoza, both excellent) just enough room to make their characters distinct and genuine, so that when they're dropped into utmost peril our empathy is engaged as much as our fear. The dynamic direction and editing make the cavern a palpable, physical presence, even before the creepy beasts crawl out of their nooks. This is not a movie for everyone; it is extremely gruesome and will induce panic attacks in anyone with even a mild fear of closed spaces. But for anyone seeking something smarter, faster, and more wrenching than static torture-fests like Saw or Hostel, The Descent will draw you into its unsettling ooze. --Bret Fetzer