When the giant insects are no longer harming Val and the others, the android Violet mysteriously turned around and dove back into the water, headed the way you came.
Having a mini-panic attack, Val called after her, and urged everyone else to also get out of the water quickly as possible, "The water here is tainted, that's why daddy built Crowfeather Palace…"
Summoning all the strength they've got, Val and Rain move to the shore to help pull the other two out of the water, after which they each collapse against cave wall or the ledge wherever there was something closest to them to support their weight.
Moments later, Violet re-emerges from under the surface of the placid, yet acrid smelling underwater stream, her hand clutching the end of the rope that must've slipped from T'Sarra during their struggle to take a foothold onto this sooty beach. Just in time to be able to hear the comment about no big wand jokes.
Her eyes darted between the tiefling and Barhuce a couple of times in confusion as they made their humorous exchange, then sized up the male briefly before handing the end of the rope back to T'Sarra and Vri, pointing out a little crack in the cavern's rock they might be able to hammer something into.
As they sort out their gear and dry off, stripping down where necessary, Rain fishes out her wand to affect the exchange with T'Sarra. Her and Val indicate their thanks to the tiefling for the healing magic.
Now that everyone is safe from the hazards of the foul water and murderous insects, one can see that the glowing glands of the dead beetles are still luminous, providing some light for about ten feet around each of the insects' bodies.
The stony beach is soot-scarred, covered here and there with scorch marks. A small underwater spring seems to wind from the north to feed this stream here, but the source of the calm, dark water continues toward the north, winding east as it follows the damp cavern.
To the east of the beach, the five foot ledge sports three stalagmites near its edge, beyond which many more seem to choke off the low-ceilinged cavern beyond, the speleothems giving the impression of some vicious maw bearing wicked needlelike teeth, gnawing down upon some dark shape on its cave floor.
A minute or so later, the feeling of illness seems to subside, and those afflicted begin to feel better.
(( Party is no longer sickened. ))