Traveling the Underdark

This is just a copy and paste of the narrative that was provided the party.

Several hours after talking with Narock, the tiefling Harper, who rescued you from the alley brawl, you are requested to join him in the receiving room of the manor. Arriving there, you find he and Melech in conversation. They quickly finish and Melech begins speaking to you. “Narock has informed me you wish to mount an expedition to challenge Lolth’s and Torog’s servants in search of the Hand of Vecna. I will provide everything I can to help you prevent either of those evil groups from obtaining such a tainted artifact. I have already arranged for a small group of Underdark explorers to join you. They are assembling everything you need and should be ready to depart within the hour.
You will need a guild as very few have delved as deep as this series of caverns goes. I believe I have found someone whom one of you will immediately recognize and trust without question, as some of you(looking at Rudy) still doubt my sincerity. Looking over his shoulder, he calls out to someone who is waiting in the hall. A well equipped, slightly aged, elf enters. You can tell by his walk, and the comfort with which he wears his armor and weapons, that he is well versed in their usage. He is extremely pale, from many years underground, almost matching Rudy’s albinoism. Allow me to introduce, Pepin.
Before much can be said, Pepin speaks up, “It is my pleasure to meet you all and learn that Leenia has risen to such prominence in the church, I could not be more proud of her. However, time is of the essence and we must get underway immediately, as the other 2 expeditions have at least a 2 day lead on us. There will be time for talk later. We leave in 1 hour. Please gather your equipment and meet us out front. Any questions?
An hour later, you exit the mansion and find a small group of ragged underdark dwellers, Uncle Pepin, Narock and Melech. Pepin immediately introduces you to the men who will be accompanying you. There is a dwarf, Det. A deep gnome, similar in appearance the Belwar, his name is Garl. Finally, a horribly scarred drow. Sydar’s hair has been burned off and his face is covered in blisters and pock marks. You will learn on the road his condition is the result of hundreds of poisonous spider bites, inflicted by the High Priestess of the city he was raised in, for some slight he won’t go into.
With the introductions over, you immediately make for the edge of town and a darkness like none of you have ever experienced. Exiting the city, you immediately feel the crushing depth as miles of earth separate you from the surface.
You make good time over the first few days as Pepin and his company set a fast pace. You can tell they are very familiar with the caves you are passing through and they each spend a little time with the group, teaching them about the ways of the Underdark. Mostly about survival, what to eat, what to hunt, how not to be hunted, etc. The number of threats is daunting and you quickly realize, without your guides, you would become hopelessly lost in mere minutes.
A few more fast paced days and Pepin informs you that you have entered the Deeps, the deepest, darkest, most dangerous part of the Underdark. Mostly unexplored, there a wonders great and hideous, waiting to be found.
Almost a full week after you set out, you hear the sound of voices approaching. They are far too loud to be someone seeking to hide or go unnoticed. Pepin quickly leads you into a side chamber and Garl performs a ritual to create the illusion to hide the entrance. You are able to witness half a dozen of Torog’s followers fleeing. They are in terrible condition. They have definitely been on the wrong end of a battle. They are all injured in one manner or another. They don’t appear to be carrying any provisions and as you know, aren’t making an effort to hide themselves. Pepin remarks, they won’t make it another 10 hours. For a group that is fond of torture, both of others and themselves, for them to flee, something truly terrifying must lay ahead.