The tunnel, now an inch or so deep in murky water flowing from the failed trap in the room the group just escaped, leads toward a door at the far end of the hall.
Glancing upwards, Garn spots that the stone blocks of the ceiling do not seem equally dark with damp: A 10-foot long block in the ceiling immediately before the door at the end of the hall hangs slightly lower, and water drops run freely down the sides from what would otherwise appear to be sealed cracks between the stones.