Lyra found a small passage leading from the lair, so we went that way. After several minutes, we found a wide spot in the hall. A crude door with a boulder on top covered a hole in the floor. A rope ladder lay coiled beside it. Past that was another cave-in. I lifted off the boulder as Mical moved the door.
An eerie greenish glow emanated from the hole. Some kind of fungus gave off the light. We could hear splashing water and something slithering through the water. Mical threw in the ladder and started descending. He paused after ten feet, and was still twenty feet above the water's surface. He shouted up that he was in the largest cavern he'd seen, mostly filled with water. He could see four passages leading away. He also heard another splash, but it was some distance away.
He climbed down to the water's surface and found it was only about two feet deep. He dropped in and waded to a dry ledge. We all followed him. As we headed to the northern passage, nine magic missiles hit Mical. He shook in the air as they pummeled him. We could see two rings of water as if two things had submerged. We saw a shadowy form fleeing. Mical quickly quaffed an extra-healing potion and continued on.
White mushrooms covered the walls and bats hung from the ceiling. Bat guano made the floor treacherous. We quickly found the north passage was a dead end and headed for the eastern one.