You notice the smell first. Nearly six thousand pounds of soil rest on the stage, so the room smells more like a farmhouse than a theater. The smell fades after a few minutes, which is precisely what playwright Bryony Lavery wants us thinking about. Her challenging new play, Dirt, is all about the tension between who we are and what we are. She creates complex situations, using meta-dialogue and the limits of the stage to create a space beyond death. It’s a delicate balance, one that nearly collapses, but is saved in its more straightforward second act.