He coughed as the dust covered him entirely and looked back where he came. It was completely dark and his witch-torch was doused. He fiddled with the pack at his side and drew the expensive brick from one of the pockets within and shone its light, waiting for the dust to settle. Sure enough, the way back was utterly blocked by tonnes of broken stonework and rock. He let himself fall back against a wall of the corridor and slide down to the ground, breathing heavily. 