Remembering where we are and wondering what you will do now
Previously, I posted this description of the stream and its adjacent passage: [sblock=Earlier Description]Johann, Dontrius, Eldran, and Yurei, and, yes, even Hraln edge up to the bank of the river to make a closer inspection. The improved vantage point allows them to see that there is a kind of shallow 'trough' dug into the wall on the far side of the stream some 2-3 inches above the water's surface, and it extends both north and south to the limits of your vision.
What this means is that if the adventurers have a way to swim the stream or otherwise cross it, they can enter this 'trough' and use it to travel along the path of the stream. The trough is cramped, to be sure, only allowing the characters to move at what we called a 'high crawl' in the army. 'High' here is somewhat deceptive, only being actually high when compared to the 'low crawl,' which will actually put you eye-to-eye with every snail and amoeba along your path, so a high crawl in armor will move you about ten feet per round, and that's being generous.[/sblock]
Given you new, but temporary, form of travel, you may have other ideas about how best to proceed. I await your good pleasure.