Shae jumps in...
Tahldar tries swimming to the edge...
They are both caught in a powerful undertow that pulls them under...
Everyone is flying through the circular wall like something in a pipe. With the pressure on your lungs and the length of the trip, holding your breath may not be enough...
Kahan loses his breath...
Shae loses her breath...
Tahldar loses his breath...
They begin to take in water (3 hp dmg each), and then the pipe-like structure opens up and pours you straight down into an underground lake.
At least the water is warm and deep enough that no one is seriously hurt. Kahan, Shae and Tahldar...all manage to catch their breaths again.
The lake stretches out to either side of the cavern walls and presses forward toward a left turn in the cavern ahead. After your plummet, you are able to move forward about 15 feet to an area that is only about chest deep.
You take a moment to catch your breath and take in the situation. The walls still glisten slightly with crystals, giving some small illumination. There is a slight undertow, but not too bad, that pulls back toward the waterfall you just came down, where the water drains somewhere below. The walls and path are as pictured below: