Beware of ancient cave paintings. They are obviously warnings to us by our ancestors. At least that is the case in the movie "Primal." Here a band of Disposable Young People (DYPs) are out camping and to look at the the paintings. One girl immmediately goes into a panic attack in the cave and gets herself cut on a stone. Oh oh, girl blood activates the whatever is there and soon enough they are being attacked by bugs, leeches, and bunnies.
Soon one of their number gets a fever and loose her teeth. It's ok though, she gets sharpie teeth and an attitude for slaughter. She gets all shouty and jumpy and tries to eat everyone else. Now our DYPs are in it deep cause the bugs ate the tires on their car. They have to try to control the who possession situation.
This is a good fast film. Very action oriented with a touch of the bizarre. We are never really given a back story, and that is a blessing actually. It works better as a really rogue bit of nature without mankind over thinking long, sharp teeth.