D&D 5E Underdark Lore: traders, locations, NPCs [Out of the Abyss spoilers]

[CapnZapp]

I'm trying to make heads and tails of the way Zhentarim is supposed to help the party find their way to Gravenhollow library in Mantol-Derith.

Ghazrim Duloc has a ring that shows the way there. But how did he get it?

(The adventure doesn't say, merely hinting how the library "wants" the party to find it. And it almost expects the party to simply take the ring possibly over Ghazrim's dead body. Why else have the secret be so easily looted? I'm asking for possibilities and suggestions to a more... satisfying... backstory, where the party actually need to interact with Ghazrim)

Also, Ghazrim being a Zhentarim and a sly one. He would want to gain something from the party and not just give up something for nothing (even if his superiors have already negotiated favors from king Bruenor and the other factions).

Are there any described movers and shakers of the Underdark that Ghazrim could be involved in? (My idea is that Ghazrim sees how the party mowes down the Duergar and hatches a plan to use their power against one of his enemies. Basically, he leads them to his enemy saying this is the path to Gravenhollow; trusting the party to go all murder-hobo on that enemy's camp since they're even more despicable than Ghazrim is)

Perhaps a rival trader? OotA doesn't dwell much on important NPCs that aren't Duergar, Svirfs or Drow (and yet aren't monsters or directly plot-related).

I've tried googling Mantol-Derith, but there are very few tidbits of information regarding the place. What I've found so far is one Laral Kroul, a half tannaruk trader that could be a good rival to Ghazrim. (And inexplicably, Grazilaxx the Mind Flayer has ended up in M-D in the Neverwinter MMO)

Any other Underdark way stations or other semi-civilized NPCs that I could use? I'm looking for a described location in the Underdark that's not a monster cave. Ideally, an Underdark equivalent to a pirate cave or coaching inn or bandit tower or trader's oasis. A base for free unaligned humanoids (that aren't primitives or brutes or garrisons for the Drow or Duergar empires), basically. Like the underdark-connected cellars of the Yartar inn Beldabar's Rest. Any edition is fine: AD&D, 4th Ed, anything.

(I know I can just transplant any map to the Underdark. Here I'm asking for lore precedents. Or is Mantol-Derith completely unique?)

And oh; any good suggestions on where the Gravenhollow ring comes from? Who could have given it to duLoc? Your wild ideas are welcome

 

[CapnZapp]

The wiki page on Mantol-Derith mentions an unnamed inn, and a small brothel.

No additional info on any significant visitors? Mercenaries, power brokers, exotic traders...?

 

[CapnZapp]

As a successful Zhentarim agent, Ghazrim must be able to put himself in a position where it is more profitable to keep him alive than to double-cross or backstab him.

Revealing there's a ring, but not being able to produce a believable story as yo from where the ring came, carries a high risk of being viewed as expendable.

The party is already looking to wipe out the Duergar completely. What would stop them from doing the same to Ghazrim?

Especially since Lorthar the Beholder is dead (the party "helped" the Drow Assassin before they killed her too).

I'll have Ghazrim claim he's had a memory of the library (and thus the ability to find his way back there) from a gas spore.

Then he'll lead them to the abandoned catacombs under Yartar. There should be a good chance the party will wipe out the Hand of Yartar leadership for him.

He is probably smart enough to let the party keep any loot he finds. Just getting rid of a business rival and getting his hand on secret business deals (and perhaps being able to influence the choice of the next crime boss) is motivation enough.

Haven't decided if he'll then simply give them the ring, or if he'll bring them to Skriss the troglodyte member of Society of Brilliance. Either way, he will claim to have upheld his part of the deal!

 

[CapnZapp]

As it turned out, my players didn't even ask how Ghazrim knew how to find the library... ;-)

I thunk I'll have him plant the ring on Laral Kroul's dead body...!