Ahead you hear the sound of rocks being ground and crushed.  The noise grows louder and suddenly you realize that the wall on your right is starting to collapse.  Terrified, you watch as a large, hideous worm-like creature with a gaping mouth and extraordinarily powerful mandibles slithers through a hole in the wall.  Its great jaws continue to crunch the rock as it turns its head slowly from side to side, feeling the cool air in the tunnel.  It appears to be totally blind, but seems to know of your presence, perhaps sensing the heat from your body.  It starts to slither toward you with its mandibles wide apart to attack.<br/><br/><em>Your choices are to fight the ROCK GRUB, or to run back down the tunnel to the junction to head east.</em>