"I could conjure a wall of fire in front of it, it's a bit taxing, but at least it should not cause too much noise while it melts the ice." answers Krom as Chill explains the situation. "Rhogar or Vellyne may have another ways to deal quickly with that ice wall." continues the dwarf looking at the dragoborn and the human wizard.

"But you do make a good point, Chill. There are no other tunnels going out from this cave. Maybe we should leave the treasure for later and continue our exploration." nods Krom scratching his beard.

As Rhogar is moving the eye down the south-eastern passage from where it currently resided, the Dragonborn reply is, "Maybe with time and a decent hand drill. But as it stands, I have not so nonviolent a means at my personal disposal. So, moving on would best." He admits. Yet rather than immediately rise and make ready to depart, he looks to Vellynne as if expecting or mildly hopeful of hearing some alternate option.

"I agree with not drawing much attention to ourselves, but if you can just give me a moment. I hope this is not a fools try." Kazri commands Oli to see if he can use his claws, and give it a one go. Oli gets up on his hind legs, and gives a swipe with his claws on the wall of ice.

Oli Strength: 16

(UGH!! I gave it a shot.)

Oli smashes his claws into the wall of ice but beyond some scratches he does nothing to it. 

Vellynne shakes her head. "I have no magic that would remove a wall of ice. I would prefer we not make any more noise than needed."

Rhogar keeps the eye moving and it enters the next cavern.

This thirty-foot-high cave has exits to the north and south. Along the western side is a fifteen-foot-diameter hole in the floor that seems to be the upper end of a tunnel.

The following features are common throughout the Caves of Hunger:

Ceilings. Most cavern ceilings are 30 feet high and made of smooth ice. Tunnel ceilings range from 10 to 15 feet high unless otherwise noted.

Darkness. All areas are cast in complete darkness unless otherwise noted.

Echoes. Sound travels quickly here. All Wisdom (Perception) checks to hear sounds in these caves have advantage.

"If a wall of fire will melt it that might be the way to go.   Let's try that. " Chill says in response to Kroms idea

"Very well then" says Krom clutching Moradin's holy symbol while taking a few steps towards the wall of ice and begins to chant an hymn of evocation.

As the dwarf finishes the hymn, the cavern floor seems to crack open as a wall of fire 4 feet long, 6 feet high is conjured in front of him.

@DM

Seeing, or more accurately in overhearing his companions determination to make some measure of headway with the wall, Rhogar just smiles faintly while continuing to direct the eye on a southward path down the tunnel still level with their own. Though he cannot help but mutter to himself, "Wonder if those two are connected in some way", referencing the hole. Even still, Gorrah sleepily chirps from the confines of the hood in agreement. 

After the failed attempt Oli lowers his head and gives a low growl of disappointment. "It is all right Oli. You gave it a good try. Let us move on." As Kazri is ready to leave their current location, Chill has other ideas. "Very well then." She stays close to the wall, but not too close, and she commands Oli to guard the entrance.

Krom's wall of fire is very effective in creating a hole in the the wall of ice that he places it against.  Within a few moments the wall is removed and another smaller cave is exposed behind it. This cave is much smaller, about 10x10 feet in size.  But you see nothing within.

"Perhaps there are further caves hidden as this one was." Vellynne offers in help

If you investigate further Chill can tell that there is probably another hollow area behind this one.

Map just above adjusted

Rhogar sends the Arcane Eye down a long passageway that leads to another large cave. On the east side of the cavern a large wall of semi-translucent ice can be seen.  This flat sheet of cloudy ice forms one wall of this forty-foot-high cavern. Something dark and humungous shifts behind the wall, its tentacles waving unimpeded.

"I could conjure another wall of fire, but we may need Moradin's blessings for future battles so let's try a different approach." says Krom as the group enters the small cavern.

As the dwarf begins to search inside his backpack he firstly places down the Professor on the cavern floor then takes out his Alchemy jug. "We always used the jug for conjuring beer or honey, but it can also create acid or oil. We could use either of them to weaken the ice wall and possibly making an opening. If that doesn't work, I'll try a more direct approach."

"Hmm.... That could be... a problem." Rhogar mutters to himself while holding a fist up under his chin. After a few moments of silent debate both with his own conscious as well as Gorrah, the Dragonborn eventually inwardly nods, before quietly addressing the party, confident in his words carrying well enough into the other chamber. "I am uncertain exactly in what I am seeing, but... something lurks within the ice itself towards the far east of here. Of course, it could be a magical projection made by some ancient artifice of some kind, or even an exceptionally enduring illusion."

"But I digress. Continue your experiments, Master Krom. Even if all you can open up is a small tunnel to the other side, so long as I can peer through it, I should be able to get to the other side and back if it comes to it." He said, then at that, proceeded to guide the eye past the lurking tentacle creature while hugging the far wall from it: a small safety measure in case the entity was attracted to other sources of magic just as it might've potentially been to living creatures.

Chill grins.  "So you are saying that the jug we've been partying out of also makes acid?   I'm not sure how I feel about that.   But sure why not.   Rhogar is scoping the tunnels with the eye thing.   That will help us navigate later as we'll know what and where to avoid.   Go ahead and splash some acid and see what happens. "

Chill moves back away from the area so he doesn't get splashed by acid. 

Krom chuckles at Chill's reply "Do not worry, Chill, the jug has different openings for each liquid." The dwarf then begins to pour acid on the wall of ice. "It would not surprise me Rhogar if it is a large undead of some kind. We may be to be extra careful if we pass near that cave. Fighting an undead underwater is not a thing that I would enjoy." says Krom as Rhogar informs the group.

Upon hearing Rhogar's report. "That is concerning Mr. Nimbatuul. Are you able to get a better look?" Kazri also gives Krom some space so he can pour the content of the jug onto the ice wall. Something comes to her mind, and she goes to Oli and command him to sit. Just in case that whatever Krom is about to pour, the Owlbear doesn't think it is honey.

"I... certainly can. But for now, I would abstain from such investigations, as typically such betentacled creatures are of an abbarent nature. And there's little telling in whether it would sense the presence of the eye and respond in some rather unfortunate way, or merely brushes aside its presence even if it can." Rhogar replied in kind while still guiding the eye along. Gorrah takes the opportunity to then project in Kazri's mind a rough image of tentacle cartoonishly squeezing a eye.

Krom works on the wall of ice by pouring acid on it.  It takes a while longer, the fire was better.  But the acid does work and eventually there is an opening large enough to fit into.  Again you find another empty chamber. But you believe there is another hollow spot behind this one.  Undeterred the next wall is taken down by the ice.

You open what you believe to be a final chamber.  Within you find a frost-covered skeleton, clad in a blue mantle. Surrounding the skeleton are the rotted remains of six ancient, leather-bound spellbooks and a cracked crystal ball. Clutched in the skeleton's hands is a staff fashioned out of chardalyn.

Vellynne reaches for the spellbooks but grunts in anger and disappointment when they fall apart in her hands and are worthless.  She looks at the crystal ball for a moment sets it aside in disgust as well. "Worthless." you hear her mutter.

Meanwhile Rhogar moves the eye further south.  He comes to a fork.  To the west he can see what looks to be a mirrored cavern.  Every surface of the twenty-foot-high cave is polished to a mirror finish.  Something lays on the ground in the center of the chamber but you can't make out what it is.

There are exits on the far side.

The south fork turns and you can't see further down it.

The following features are common throughout the Caves of Hunger:

Ceilings. Most cavern ceilings are 30 feet high and made of smooth ice. Tunnel ceilings range from 10 to 15 feet high unless otherwise noted.

Darkness. All areas are cast in complete darkness unless otherwise noted.

Echoes. Sound travels quickly here. All Wisdom (Perception) checks to hear sounds in these caves have advantage.

"So that undead was a wizard." says Krom, with a hint of disappointmen, as the group enter the last chamber. "A staff made of chardalyn...it may be dangerous to use." continue the dwarf as he asks Rhogar "What do you think?"

"As for continuing our exploration of this complex, I think that we should check the paths that the eye didn't take and keep using it to scout ahead. At least as long as the enchantment lasts." says Krom "Beside that strange creature, did the eye find out anything worth further exploring?" 

Rhogar seemed to become pensive over the questions. But after a moment or two, he finally nods while sending the eye in for a closer inspection on the object in the center of its current chamber.  "It's closer to a theory at this point, but... do you remember the great tunnel leading downward in the tower room we past through? Well, I discovered another that seemed in passing to be of a similar make a little east from here. And though I cannot honestly account for the veracity of this next statement, it may be possible that these more underground oriented tunnels could be connected, and may even serve as a 'shortcut' between various points within the glacier.If so, then it may behooves us to avail ourselves of them, if perhaps to avoid stumbling our way down too many of the more contested areas."

"... As for the staff, there would no doubt be some risks involved in its use. But, if Vellynne there can make use of it, then leave it in her care or bag it for now. The choice is up to the rest of you."

"I don't need a staff.  It will just slow me down.  If Vellynee wants it, fine with me." Chill remarks "That mantle is still in really good shape, magical for certain.  Grab it at least and we can figure out what it does later."  

If no one else does, Chill will remove the mantle from the skeleton and stuff it in his bag.

"I'm ready to move on, wherever we decide to go. We are trying to find the entrance to the fallen city right?"