I can't say if "The Cavern" is a ripoff of "The Cave" because I haven't seen that. I've seen "The Descent" and that's not terrible but it is very hard to watch and so is this one. Hard to watch, as in, there's very little light and lots of fast motion so you're hard pressed to say what you're looking at. There are times when I guess, you're supposed to be scared, judging from the music, but scared of what? Bad camera work? Poor lighting? If that's the case than this should be the scariest movie made. The story is that a bunch of cave explorers go to a cave in Kazakhstan (home of Borat) and make their descent, but something is (of course) in there with them. And what is it? One guy says it's a wolf/bear hybrid, that is, just before he gets ripped apart, but whatever it is, you can't see it. And just when you think (or hope) the film is ending, since the screen goes dark for a bit, you see the two remaining cavers (the two women) wake up somewhere in Betty and Wilma attire and start trying to find their way out of wherever they are. They do drink some water and start eating SOMETHING until they figure out what it is and start puking....and then the mystery of what's in the cave appears, and you'll just be astounded. Maybe, maybe not. Dumb dumb dumb....I think I'm pretty well done with cave movies at this point, 2 out of 10.