''Hey, there's something down here.''
There is no equal to this horror film within the last few years. It's better than the terror of 2005's Wolf Creek, and while not having the epic quality of 2003's 28 Days Later, it scares you with class and restraint a bit like Open Water but inside the earth. It is a distaff Deliverance (1972), every bit as macho, every bit as scary in its suggestion of human and inhuman depravity.
Six British ladies go spelunking in our Appalachians. Besides the discovery that these caves have never been charted is the terrible recognition that they are not alone two miles into the adventure. As if getting lost and stuck were not horrible, the girls face a humanoid clan that finds flesh a happy meal for what must be limited cuisine at the center of the earth.
Although the crew faces some pretty disastrous events before seeing the light, director Neil Marshall never allows them to degenerate into the usually ranting females of other slasher films. These are competent women (one is a med student) whom we saw in the title sequence negotiating at least a class 6 rafting river. Sarah (Shauna Macdonald) lost a daughter and husband in an auto accident after that rafting trip and faces her late husband's affair with Juno (Natalie Mendoza), so writer Marshall has built in emotional tension to parallel the physical horror.
The camera work is agile and the lighting realistic enough to allow the head lamps and flares to do their job yet not deprive us of creepy monster images and scary false turns. The gore is about as vivid as any I have seen recently in the slasher mode, and the monsters, while not as horrific as Alien's, are memorable for their reasonably thought-out physiognomy with useless eyes and bat-like instincts. Where these monsters came from is perhaps a story for another time, for this cave-in is story enough.