I suppose you'd call this a Saw clone, with a mad scientist type capturing five people for an experiment. Once upon a time, the scientist was trapped in a car wreck with his dead mother and ended up eating part of her to stay alive. Now he wants to push people into the same choice. He throws them in a sealed up cave, gives them plenty of water and a knife, and waits.
The movie unfolds about as you'd expect, with the people holding out for weeks before some of them snap and start the eatin'. Though mostly lacking in surprises, it has a fairly nice build-up of tension. My biggest issue with the movie is the starvation aspect of it. After 30 days without food, these folks are really energetic. They fight and run and break locks of doors. The final girl even climbs up a 30-foot rope ladder after 36 days of no eating. I just couldn't suspend my disbelief that much (especially considering the actors looked the same weight as they did at the beginning of the film). Then again, maybe you can pull that energy out of yourself even without eating for that long? I dunno. (6/10)