> go back through door
Done. The large door slowly creaks shut behind you.
You remember this area from earlier. Behind you stand an enormous wooden door, and surrounding you are various stalactites and stalagmites protruding from the celing and floor respectively. The walls around you are wet and slippery, and this room definitely gives you the feeling of being in a cave. In fact, that's exactly where you are.
You also notice that the corpse of the Grue that you killed earlier with your extreme sarcasm has mysteriously disappeared. Perhaps it has been eaten by an even larger Grue.