This 2011 second feature by British director Ben Wheatly (Down Terrace) may contain some art-movie flourishes (Cassavetes-style improvisation, an avant-garde score), but at heart it’s just an exploitation film whose chief aim is to make people throw up. Two sadistic army veterans put their torture skills to use by becoming contract killers; after taking a job from a mysterious old man, they’re drawn into a waking nightmare. Wheatly aims for something like moral complexity by having one of the killers believe in God and the other aspire to be a good husband and father, but once the graphic violence starts, it upstages everything else. Squint hard and you might see an antiwar allegory.