You steer your boat into the fork on the left. You coast steadily forward, the passage around you gradually growing larger and the current slowing until your boat floats into another underground lake. The lake is big enough that you can't see the farthest walls. You hear a strange sound, almost like a rumble. A moment later your boat is rocked by a series of waves. A low-pitched groan echoes through cavern so loudly you feel your chest vibrate. All you can see ahead of you is a single-room shack on what appears to be a tiny wooden platform atop the water. A warm yellow light glows in the windows. You row towards it. Once you reach the platform, you find a convenient pole with a rope with which to secure your boat. You see no other boats, but hear sounds coming from within the cabin as if someone is inside moving around. You can knock on the door, peek in the windows, or you can hide and wait to see if anyone comes out. You can also try using your flashlight or whistle.