Anton Yelchin (“Star Trek”, “Like Crazy”), Imogen Poots and a bunch of other people are trapped inside a room following a punk rock concert. Why? Because one of them witnessed a murder. Now they are forced to fight their way out before they get viciously killed by a group of crazy skinheads, lead by Patrick Stewart in an amusing (if weird) role. Nothing you haven’t seen before. But the fun is in the techniques. Writer director Jeremy Saulnier puts us right in the middle of the action in a way that we feel trapped inside with them. Other movies have been there before, of course, but for fans of the genre, “Green Room” more than delivers the good. As someone who had no idea what to expect from it, I came away pleasantly surprised.