if your looking for a intellegently done action move with elements of horror then this is the movie for youit is about a team of explores that are spelunking a recently uncovered cave system that goes on for miles under a mountain range. The cave had been capped of by a church built in midevil times reputed to be thier to keep demons in.once in the cave they find that thier getting more than they bargened for as they descover the presence of a strang mutating parasite as well as a host of life forms previously unseen beforeas well as a bat like prediture determined to hunt them down