Jhazaal casts guidance on himself, then jumps into the webs alongside his companions.  He works to pull free so he can fall to the water below, then would high-tail it to shore.

Athletics: 14

Guidance: 1

Buppido shrugs and jumps into the webs after the others.

Athletics: 5

And gets wrapped up in webs he cannot break free of easily.

Vera will wait till every other member of their group has descended into the webbing.  "Elistraee guide us" she whispers to herself before jumping down and joining the others.

STR check: 3 

Landing awkwardly as she tried to avoid her comrades, she gets tangled up within the webbing and struggles to break free.

Wendigo hops down after them, attempting to slip through the hole Knox has already made.

STR Check: 19

He rips straight through, falling like a rock.

Brio encourages the young deep gnomes along with the rest of the group to hurry down until it is just her and Vera left. "I'll see you down there friend." Brio then jumps down aiming for an area already weakened or opened up. 

Str 16

Bupiddo, Hawthorn and Vera get stuck.

NPCs:

Derendil: 17

Eldeth: 2

Jimjar: 1

Ront decides to try his luck somewhere else, and runs off into the complex.

Sarith: 8

Shuushar: 13

Stool: 10

Topsy and Turvy also vanish off into the compound.

All the NPCs but Shuushar and Stool make it.  It's now round two, and the grey ooze is now within striking distance of those in the water.

Inits (oh boy, this is going to take a while):

Bupiddo: 7

Derendil: 15

Eldeth: 16

Jimjar: 8

Sarith: 4

Shuushar: 13

Stool: 19

Ooze: 7

Wendigo: 21

Brio: 6

Hawthorn: 7

Jhazaal: 9

Knox: 7

Vera: 16

Jimjar scrambles frantically out of the pool, muttering something about "not taking that bet."  He'll shoot a hand crossbow at the ooze.

Attack: 24 Damage: 3

Sarith curses in Undercommon under his breath, and also fires a hand crossbow at the ooze.

Attack: 19 Damage: 3 Ooze save for poison if it hits (DC 13): 11

The ooze falls unconscious due to Sarith's poisoned dart.  Jimjar's bolt misses, his hand shaking in fear.

(Wendigo, Jhazaal, Vera and Bupiddo are up)

Those still in the webs feel them tremble slightly, and see three giant spiders approaching from a distance.  They'll reach you in about 2 rounds.

Wendigo brandishes his axes and rushes towards his stuck allies, cutting away at the web around them.

Attack: 20 Damage: 8

Attack: 22 Damage: 1

If a check is needed instead, flat D20 without any modifiers: 10

(Hopefully I didn't just take Bupiddo's foot off)

Wendigo barely misses Bupiddo's foot with his first strike, but lands a solid chop on the webs.  They quiver, but don't break.

(Jhazaal, Vera and Bupiddo are up)

"Damn it" Vera exclaims as she wriggles in the webbing trying to break free.  A moment later, she stops as three particularly large spiders heading her way enter her vision.  Seeing them approach, she restarts her escape attempt with renewed vigor.

Strength check: 10

Buppido tries to break free...

17

Jhazaal swims to the shore, content to let the ooze sleep if possible.

On hitting the water Buppido uses his movement to swim to the shore.

Vera and Bupiddo both manage to break free.

The ooze is unconscious.

Shushaar attempts to break free again: 17

As does Stool: 5 

Shushaar manages to break free, but Stool remains stuck in the webbing.  He's shaking in terror as the spiders close in . . .

Derendil grunts, and smashes the unconscious ooze with his claws.

Attack 1: 23 Damage: 12

Attack 2: 19 Damage: 10

(Hawthorn, Brio and Knox are up)

(Derendil has clawed the ooze to pieces.  He looks up, seeming to search for more prey.)

Brio quickly makes a small mechanical ball that lets out the sound of a horrifying bestial roar and hurls it at an angle to the spiders, trying to distract them from the group. (Using magical tinkering)

When Knox first enters the water, it looks like he is going to sink, but he opens his mouth and sucks in air, before closing his mouth again.

Now buoyant enough to tread water, Knox watches as his fellow escapees follow him down, some getting stuck, others making it down to the water and then swimming over to the shore.

Knox follows the others, swimming to the shore and climbing out.

Knox looks up at those still stuck in the webbing above, considering his options.

This webbing is about 30 feet away.

One of the spiders goes off to examine Brio's trinket, but the others are too focused on the tactile warnings they're getting from their web.

Knox speaks an arcane word and flicks his hand and it bursts into flame.

Taking aim, Knox throws the flame from his hand, targeting the nearby webbing, trying to help break it.