Ravage is essentially a campfire story for mature audiences: there’s a lot of build up, an unsettling suggestion of what could happen, and then a freaky follow through.  What we learn throughout the film, however, is that writer/director Teddy Grennan and the film’s nincompoop producers are incapable of closing their set-ups.  This is demonstrated by some earlier mini murders, making us apprehensive about its grand finale when a ludicrous torture chamber is invented and utterly…