Ox, you'll have to make a Strength Save to avoid meeting the same fate as Dane. If you succeed on the save Nylia can easily toss you a rope and pull you back up.

Strength Save: 2

Well, looks like I'm dead. (If I succeeded, I would've grabbed the rope and tried pulling Nylia down.)

As I start being swept away by the water, I scream, "NEVER SPLIT THE PARTY!"

Nylia stands alone above the chasm, watching the waters where her two companions were just seconds ago.

She stands, motionless as the two vanish. She hasn't known them for long. All the same, she closes her eyes, prays silently in their names that their souls may rest.

Nylia looks toward the dark tunnel behind her - she's unable to go back.

So she moves forward, her shield and sword as her remaining steadfast allies.

Nylia, the tunnel widens before you, and you proceed through the damp aperture before it eventually stops in front of a rotting wooden door, crusted with seaweed and salt. A message is carved in the face of the door in Common. Herein lies the hoard of Drago the Drowned. Make ye not the mistake he did.

Ox and Dane, you awake on the rocky shore of a vast underground lake. The titanic cavern in which you find yourself is illuminated by strange bioluminescent fungi which coat the walls and floor. You are drenched and missing your packs and equipment.

(You may choose one weapon from among your equipment. The rest has sunk to the bottom of the lake.)

Nylia reads the inscription and remembers the story that the bard had told in the tavern a few nights ago. She figures that she's fine as long as she doesn't go hungry for gold or undeath - two things she doesn't much care for at the moment.

She opens the door slowly.

(Should I go ahead and wipe my equipment page then?  I'm keeping my shield, unless my holy symbol would have also disappeared, in which case, I'll keep the symbol.)

"Bah.  I am never leaving land again after this.  You, are you alright?  Thanks for coming after me."

(You can keep both the shield and holy symbol.)

(Fabulous, I'll do that, and wipe the rest of my equipment)

(Fantastic, this is why Ox normally is a jerk. Lets you keep your stuff.)

I will keep my Double-Bladed Scimitar, and wipe everything else clean. 

Nylia, the door creaks open into a chamber that appears to be hewn from solid stone. In a layer of water three inches deep floats a hoard of coins, rusted armor and weapons, and other odd items. A statue of pale stone stands in the center of the chamber, surrounded by the memories of days long past. It depicts a life-sized man with a cutlass and a long tailcoat.

Ox and Dane, as you look around to get your bearings, you notice dark shapes cutting through the water of the underground lake. A moment later two merfolk surface. Their flesh is pale and their eyes are covered in a thin layer of film. The merfolk do not make any openly hostile moves, but continue to watch you from a distance of thirty feet. Perhaps ‘watch’ is not the right word.

I turn back to them, startled and give out a small scream. I stand up and point the tip of my blade at one of them, asking, "Who are you?!"

Insight: 13

Perception: 18

(Explain their appearance to me, please?)

Something like this, but even paler, as if they have never seen the sunlight. They are also blind and have no hair.

(Is there supposed to be a picture there?)

Nylia looks for a door that continues down the path, or any secret doors. 

Perception: 15

Dane is not as aggressive here as Ox, but he also readies for some kind of fight.  He's not going to take anything else for granted now.  He will also try to get a read on these creatures

Insight 12

Perception 13

"Who are you?  Where are we?"

Quote from PoorTom >>

Something like this, but even paler, as if they have never seen the sunlight. They are also blind and have no hair.

 (If there's an image here, I can't see it.)

https://i.pinimg.com/474x/33/85/97/33859721e1892225d6ccacf2ce739183.jpg

(There's the URL for it)

(Ah, that's blocked on my computer.)