((I'll work under the assumption its the new passage to the right that closed off.))

Pensive works his way over the top of the rocks to see what is one the other side.  Kaylyn keeps track of his progress through Pensive's senses, ready to dismiss him if trouble appears. 

(Any fungi/mushroom in this area??)

Sorry, I meant the way back is blocked (blue pentagon). But I'll include a rockfall in the right-side passage as well (red pentagon). Pax is clearing rocks at the blue, Pensive is exploring past the red up to the green star.

Pensive squeezes past the other rockfall and travels along the short tunnel. At the far end the pseudodragon spots what appears to be an old lair. Small teeth and bones lie scattered among crude implements and old filth around the edges of the cave. However in the center of the cave are two humanoid skeletons, the bones of which are completely intact and unusually clean.

Kaylyn: Make a Nature check. Can use your Wisdom for this one instead of Intelligence.

Rhayna: No, there is a noticeable lack of fungi in the area. The tunnels and the first room don't even appear to have any of the light mosses or lichens that typically grow almost everywhere else in the Underdark.

Sekkar helps Pax to widen the path back. "There is something in here -- does not talk but you can feel it in your mind." (He paused to -- in thoughts -- thank Dawngringer for alertness) "There is nothing growing here on the walls, and that puddles of slime -- everything screams "Ooze". Nasty things, something you do not want to be with in the same tunnel."

Nature 21

Kaylyn instructs Pensive to take a closer look at the remains.  Why are they so clean?  Something nags at the back of her mind and she tries to recall what creature may do such a thing.

"It is very strange that there is no sign of fungi here." Rhayna gets closer to the room and tries to discern what kind of construction if the room made of. (History: 14)

Pensive examines the remains more closely, with Kaylyn receiving the images telepathically. The shape of the skulls resembles a troglodyte head. The bones seems to have had the flesh dissolved right off them, leaving them starkly white and completely free of muscles, sinews or other soft tissue.

Rhayna pokes her head inside the room and looks around. The construction has elven features, and is most likely of drow origin, but quite ancient. A close look at the walls reveals them to be inscribed or carved with repeating motifs of a stylized eye. Remnants of purple, black and green pigments adorn the designs. The symbol is duplicated in such as way as to create a flowing pattern on the walls that is rather disturbing to look at. Rhayna recognises the symbol as belonging to Ghaunadaur, The Elder Eye, The Lord of Slime, God of Abominations, a rather obscure deity once worshipped by the drow, and concludes that this structure was once a temple or shrine.

The water flows into the room at an increasing rate, and begins to pool around Rhayna's feet and seep into the tunnel. Rhayna makes a quick calculation in her head and judges that the water level could very well rise above head height much sooner than her companions can clear the blockages in the tunnels. While thinking on this, Rhayna feels a telepathic prod in her mind, accompanied by the thought: What are you? Have you come to help? Rhayna turns her eyes to the northern corridor and imagines she can catch a glimpse of a slow-moving humanoid figure, but it is too dark to tell for sure.

Pax looks back to see water running rapidly down the passage, then glances at the pile of rubble her and Sekkar have barely made a dent in. She picks up her backpack, tapping Sekkar on the shoulder, "We're out of time for that option. Say friend, can you breath underwater. You might be one of the few of us to get out of this one alive." 

She glances around....  and as she's buckling her sword belt back on she says out loud, "Is there another way out of here?  Preferably a passage that slants upwards?"

Glancing back at the rubble...there was a gap through it, right?  If she had to, does she think she could Misty Step through there?

Yes, could definitely Misty Step through the gap.

Sekkar doesn't breathe underwater I don't think, but can hold breath for long periods.

"Breath - no, but can dive for longer than others. If water comes, for a hour we can hide in the rope-hut, but then will need to find a way out. Though with that gap the water flow will eventually wash away some rubble and we would leave. The question is, how fast."

“Greetings. Are you a follower of Ghaunadaur? What aid do you need? Perhaps we can help, but right now we have a little problem with this water coming into this place. Are you able to stop it?” Rhayna takes a step forward closer to the creature. “My name is Rhayna, and I am myself a follower of The Lady... I mean, of the Moonmaden.”

Zeno looks around for anyway to help, then decides to carefully step inside the room, raising the hood of his cloak as he does.

Kaylyn informs the others of what she has found out.

"The other blocked passage seems to lead nowhere.  There are some skeletons, likely troglodytes, and the bones seems to have had the flesh dissolved right off them.  They have been left starkly white and completely free of muscles, sinews or other soft tissue.  I am not seeing anything at the moment that would cause such a thing to occur.  The area is small enough that even an invisible creature would be noticed by Pensive, he sees very well in the dark and can perceive his surroundings without relying on sight, though only to several feet away."

If there is nothing else there then come back Pensive She tells the pseudodragon.

She'll then move to join the others.

"Oozes," repeated Sekkar still trying to dig up big enough whole for everyone to climb out of the trap. "Just another proof. Can hide in the water perfectly, you would never know when one is coming." He kicked a particularly stubborn rock and looked at the gathering water - how long did they get until the rooms are flooded?

(At its current rate, you might guess that there is no more than an hour before the water reaches head height.)

The voice in Rhayna's head doesn't speak words, but still comes through patchy, almost like one that is not accustomed to communication. I don't... follow. I lead. The one that awakened me... said I should find others like me... gather them... lead them to the feast. Are you like me? The... water? Oh, yes. No. I can't stop it. But there is... something... that can help. I lead. You follow?

Taking a step closer to what she assumes is the source of the voice, Rhayna sees what appears to be a humanoid skeleton in the dark corridor. But it seems to be floating a little above the ground. A little further down the corridor the water seems to be pooling behind some kind of barrier, but in the dark Rhayna can't make out any more details.

Seeing nothing else of interest to its master, Pensive returns to Kaylyn through the gap in the rockfall.

Zeno quietly enters the room behind Rhayna and looks furtively around. Sekkar's last comment is barely spoken when, as an ironic exclamation mark, five large grey blobs of slime drops from the ceiling, one of them directly above Zeno, another above Rhayna, and the other three landing in the water with a loud slap!

Initiative!

Grey Oozes: 17
OMDV (Owner of Mysterious Disembodied Voice): 2

Wow, nice roll, oozes. Thank you, we do try despite our limited agility. This is your day to shine, own it!
... Wait, who am I talking to? Everyone knows oozes can't talk!

If Rhayna or Zeno can roll above 17 (such a great roll), they can act first. Anyone not in the room cannot act first round, same as if they were surprised, but can still roll initiative. Don't get too concerned though. Despite your most gallant efforts, it is likely to be a very brief combat, owing to the most excellent rolling of the mighty oozes.

[Somehow managed to duplicate the entire post twice. Redundant duplicates deleted, kept initial rolls, but errors have resulted.]

[Fixed]

Sekkar Initiative: 6 (They took my rolls!)

Rhayna Initiative: 27

"We can never just have it easy for a bit huh?" Kastix screams.

Initiative: 12

Rhayna is able to see the ooze dropping from the ceiling just in time to get out of its way. She grabs her Drow Zurkhwood Staff with both hands, concentrates for a moment summoning the spores inside of her body, and the staff is covered in fungi and spore in moments. (Cast [spell]Shillelagh[/spell as BA) She then hits the ooze that landed next to her with her fungi/spore infused staff.

Staff Attack: 19 Damage: 6

After landing a solid hit on the slime, to which she was surprised herself. "Well, I am not exactly like you, but perhaps a little similar?" Rhayna replies to the voice, looking at the skeleton, but still keeping an eye on the slime next to her. "I am not exactly into slimes, but I do have spores circulating in my body..." She gives a slight cringy look. "At any rate. Who or what are you gathering, and can you tell me more about this feast?"