Tryn comes to see empty corridor, while (i accept your canceled action, since there is no immediate threat, and it will speed things up) Goraseth enters ruined room full of rubble.

"An empty corridor with a dead end?" Wonders Tryn out loud. "That looks suspiciously like another secret door." Tryn begins to investigate methodological the corridor for evidence for a secret passage (Perception: 15; Investigation: 21).

Tryncaryn hunch proves to be correct and he finds another secret doors, that lead to main chamber.

"Here's the main chamber with the altar, it seems. Let's check out first what Goraseth found." Tryn closes the door and follows Goraseth.

Goraseth will look in the rubble very carefully, in cas an ooze is hiding in there.

investigation: 18

nothing in the rubble and in whole room. if not for all the rubble and rocks, that chamber would be empty.

"Nothing here," Tryn states disappointedly. "Let's check out the altar room?" Tryn will lead if the others want but he will wait until everyone is ready to follow. 

"Agree... let be still on our guard"

Perception: 20

Progo will try to see if he can determine that there is an exit blocked by the rubble in the room Goraseth searched. "Progo finds it very odd, all the secret entry ways to this place. Either there is more behind the blockage, or something important to be able to leave with quickly was in here. Extra guards perhaps?"

Progo will walk around the outside walls of the main chamber. Whike along the back wall he will investigate the pulpit for traps. 

Investigation 7

Perception 10

"Progo finds traps are in high traveled areas, most highly traveled areas are not long the wall as thise who set traps still need a easy and safe way through."

Progo  finds nothing. That does not mean he was not right with his thoughts. But even if he was, the avalanche took it out away, and now there is only rubble. and ruined room.

So Tryncaryn waits for everyone before entering main chamber. Goraseth coming in smells not one but two sources of spoken ooze.

/I take it that you all enter the main chamber, but thanks to Goraseth roll i am showing you where oozes are. You can state different placement of your characters, before fight starts, than i have shown./

Your team starts the first round of combat. Jellies come second.

Tryncarryn was already almost in the middle of the large chamber when he suddenly noticed the movements of what he initially perceived as two huge sand mounds. "The jellies!" he cries out and jumps a little backwards in shock. Not wasting a moment, however, he draws his staff and beats the jelly. For good measure, he adds a solid kick, too. These monsters are a lot bigger than he assumed. At least that makes them easy to hit but they might hit hard themselves, he ponders. 

Move: to H8
Action: draw quarterstaff and attack (one hand); hit: 19 for 7 mundane bludgeoning damage
Bonus: unarmed strike; hit: 23 for 5 mundane bludgeoning damage
(rolled everything in AboveVTT, hope that worked.)

Both attacks hit. And hitting it feels like hitting hard mass. It seems to harden itself on impact, but loose itself when moving.

oh and ochre jelly that is further north (with blue 0 mark) is on the ceiling. still reachable to attack (since it is big and ceilings are only at 10 feet)

Progo, worried about being trapped in the passage way after hearing there are more then one of these jellies. Sprinting (BA dash and movement to run around the corridor and come out in the main doors (E10) and aim for one Tryncarryn hit:

Attack: 8 Damage: 16 with sneak

Goraseth jumps into action , he flicks the torch on the floor to keep some light in the room and be able to draw his weapon. « So that’s a jelly !!! » he says with a large smile.

free action : dropping the torch, placing himself on the front line, between the jellies
bonus action: casting shield of faith (ac now 21)
action : attack with his Yklwa 13, 6 piercing damage

With Seth out of the way, Tharanau follows more slowly and stops at the entry. From there he tries to attack the jelly that is far away (blue 0) with a ray of ice to hopefully slow it down. (15 to hit for 2 dmg).

then he retreats back into the hallway. 

Progo your arrow slinks into the ooze mass and leaves a gap in the ooze that is not closing itself. (attack hits)

Goraseth i assumed you would go to I 7 (correct me if i am wrong) and your attack hits giving similar effect as progos arrow.

Tharanaus attack also hits and whole ooze is frosted up from the point of impact of the ray.

Blue ring ooze attacks back at Tryncaryn (15 attack) for 7 bludgeoning damage and 1 acid damage.

Green ring ooze stays in place on the ceiling.

Progo will take a moment to breath and line up his next shot (Bonus Action Steady Aim) curious that the block on the ceiling made no moment after being shot. No retreat, no advance, just stunned by Progo's attention.

Progo shoots the same cube:

Attack: 19 Damage: 7 plus 7 sneak

Tryn reels back a little from the blow he received and shakes his arm as if he wants to put out flames, "This burns!" Nevertheless, he attacks against relentlessly, after getting his bearings back. "Good shot Tharanau! You froze the second one right in place. Can you do that again?"

Move: none
Action: attack with quarterstaff (one hand); hit: 22 for 5 mundane bludgeoning damage
Bonus: unarmed strike; hit: 8 for 5 mundane bludgeoning damage

Goraseth continue to attack the ooze, keeping an eye on the one on the ceiling.

Attack: 15, damage 11

Tharanau his again the ooze with a ray of frost (to hit 17, dmg 6).