Ok, waiting for you guys. Do you want a map to make it easier to visualize things? Although since this is getting into 3d stuff... and you're traveling... it might not help that much...
You're in a cavern that's like 10 feet high, 30 feet wide, and 60 feet long. There is a stream running along the side opposite from you and the mucklestone that is 5 feet wide. The barghest is saying that you have to swim down into the stream and under the "wall" on the opposite side of the stream, and swim underwater for a bit to get into the aboleth's area. The underwater part is only a short distance, though. Then there will be an area with an underground lake dotted with islands (I didn't explicitly mention this in the IC thread, but lets assume that he tells you about it. He's of course quite cooperative and willing to answer questions... seeing as he has no choice in the matter.
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