The party travels along the path Narstin believes Glabbagool took, until he arrives to a place where a skirmish seems to have occurred.  The same booted footprints he saw earlier near the camp show a brief battle that ends near a wall with a fissure, where Glabbagool's trail can no longer be followed.

Ahead is a very large cavern and Narstin can see a non-natural large set of honest to god stairs ramping upward.  The cavern is large enough that other paths and exits must surely exist beyond in the darkness.

Skameros looks in to the fissure Glabagool disappeared in to - maybe lightning strikes twice

Skameros smushes his face into the cavern wall all around the fissure, pushing as hard as he can, but this appears to just be a fissure.  Large enough to get an arm and a leg into, but not enough for a torso, regardless of race.

Rodolfo says, "Well, we have arrived somewhere it seems. On one hand it's good to have choices, but on the other hand it's up to us now to make the correct one. I'm wondering if should maybe take a look around first to see what our options are and then make a decision about the path we wish to follow?"

He takes another look at the stairs, "In theory up seems good, but lets see what else is here. In a place as large as this there might even be a signpost or something. But lets be quick about it as well because there is surely traffic coming through here."

Rodolfo said there might be a signpost or something? Beegred wanders around, hoping his passive perception (19) or passive investigation (16) will alert him to anything worth checking in more detail.

Exploring about, Narstin's hunch is correct.  This is a large cavern with many exits, that actually wraps around the back of the stairs.  There are no signposts, and even Skameros knows the underdark races don't advertise the locations of their cities, villages and outposts.  Often travelers find themselves at the gates of those cities after turning a nondescript corner.

Narstin Survival (with advantage from help) DC 15 check: 20

After Skameros futilely presses his face all around the fissure Narstin told him Glabbagool fled into, Rodolfo takes a closer look to discern where it may go.  The fissure is natural, is jagged, bends and twists such that it is not possible to see very far into it.  There's no way to discern or intuit where it may go.

Deciding among each other, a weary eye on the ominous set of massive stairs, the party decides to follow the small booted footprints to see where they came from.  Narstin examines them carefully and sets out, party in tow.  It doesn't take much time to realize the tracks don't come from the stairs.  In fact, the route they take seem to take great care to avoid being seen from the direction of the stairs, as the party walks in low depressions, natural ditches, in cover of large stalagmites and so on.  Eventually the tracks lead to the backside of the massive pillar the stairs are carved into, where a grouping of stalagmites naturally hides a small natural looking tunnel.  To Narstin's divine eyes, it is evident that a lot of traffic enters and exits this tunnel, and efforts are taken to cover up the tracks.

The only other thing of note, as you stand among the stalagmites hiding the tunnel, is the size of the opening.  Beegred, Jimjar and Rodolfo will pass without too much effort.  Narstin's wide shoulders and barrel torso will require some effort, and Skameros will just plain have a difficult time entering and traversing such a tunnel, unless it widens further in.

Standing in front of the tunnel, Skameros makes it clear he doesn't want to squeeze himself into there.  The party decides to explore the stairs.

Circling around the massive pillar, everyone looks up the stairs hopefully, dreaming of the surface.  The stairs are odd, much too small for Narstin and Skameros and irregular in such a way that it makes traversing them a task that requires their full attention.  Once arriving at the top, a massive door stands shut.  Narstin recognizes some of the materials used in the construction of the door; Mithril, Adamantine, Iron.  Rodolfo recognizes that the door is magicked to withstand magical attacks.  Even the floor of the terrace leading to the door is sloped, to make ramming it difficult.

To the left, there is a platform with a massive chain trailing down into a ramp, tied to a massive sled.  The sled currently blocks the whole passage of that ramp.  Narstin intuits it is probably a way of hauling up entire carts, bypassing the stairs.

The entire terrace is nondescript.  The only other features of note are numerous empty recession in the otherwise smooth surface of the walls.  Here and there, seemingly at random, are gems laid into those recessions.

Skameros will take the flat of his greataxe and knock on the door

Not long after knocking on the door, a voice can be heard (but the speaker can't be seen) replying in Undercommon, "We see you strangers.  A bugbear and surfacers?  Explain how that came about, and what business you have in Blingdenstone."

Rodolfo looks at others, only understanding a couple of words, "What did they say? Is this Blingdenstone? Did we actually arrive here safely? Yay!"

Skameros turns to the rest of the party and says

"Welcome to Blending Stone, home of dirt nomes'

Quote from Kerrec >>

Narstin recognizes some of the materials used in the construction of the door; Mithril, Adamantine, Iron.  Rodolfo recognizes that the door is magicked to withstand magical attacks.

Beegred ponders if a chunk of Mithril or Adamantine could be broken off somehow. Might bring a tidy sum of gold.

But he stops prying at the door after the voice from inside calls out. For all the studying he has done of the Underdark, still can't understand a word.

"Thanks for the translation, Skameros. So we actually made it to Blendersting, huh?"

"That what voice just said.  They also ask why we here..."

Rodolfo says with a big smile on his face, "Well, tell them!"

The voice responds, in Common, "Yes, do tell us.  What is a bugbear doing with a bunch of surfacers in front of the gates to the inner city of Blingdenstone?"

(oh I hope I recall correctly)

Rodolfo looks around for the source of the voice, "We found him. The myconids of Neverlight Grove found him before we did. He didn't have much anything to do there, so he came along with us. Also, something really strange and dark was happening with the myconids, so we made haste leaving that place."

He looks around at the others, "Do you mind if we come in? We have been heading this way for many many days and are very weary."

"I knew we'd make it eventually!" Narstin exclaims.  

The voice echoes, sounding confused and disbelieving, "The myconids from where?  You've been heading here for many days, but you haven't said why.  If you're looking for trade, the mushroom farms can sell you food.  If you're looking for goods, all we have to barter is salt and raw ores.  You can find all those at the mines on the outskirts.  No need to enter Blingdenstone for that."

"Neverlight Grove," Narstin says.  "It's a few days from travel from here.  One of our party is from Blingdenstone," Narstin adds as he turns to look to Jimjar.  He pauses as he doesn't see the gnome with the rest of the group.  Looking to the others, he asks, "Where's Jimjar?  He was just with us..."

(Unless we want to go look for Jimjar or have a longer discussion first:)

Turning back to the door, Narstin says, "I'm not sure where he went, maybe he needed a rest getting up those steps and lagged behind a bit.  But we are all from the surface and have become lost down here in the underdark.  We're trying to find our way back to the surface, and it was suggested to us that if we came to blingdenstone here, you might be able to show us how to reach Gauntlgrym, from which we could make our way out."

(I forget exactly how long it's been from neverlight grove, but can always substitute "a few days" for a longer timeframe if it's been much longer)