Rumbling stone was nerve wracking. The cave seemed to drop more dust on the group than expected. There were some cracks that seemed made intentionally to let the stone door fall in to empty spaces on the sides of the walls. The other cracks were caused by time. That means some of the stone door fell away and blocked the tunnel from easy travel. However, it was nothing for Walker since he was able to use the earth sculpting skill to keep the cracks from forming on the walls around him, especially the ceiling. It kept the tunnel's integrity intact.