These underground "tunnels" were inhabited by Yuan-ti cultists. The Revengers were sent here on a mission by Ivan Blackstone (who would later be revealed to be a doppelganger) to find and rescue his daughter. Taking a discovered Circle of Teleportation in a room hidden in a cave system, the party interrupted a sacrificial ritual in progress. A large battle broke out between The Revengers and the cultists (led by Archpriest Thrax), with the party victorious. However, no signs of any dwarven girl were found.
Top floor: This room seems to function as an entrance, with a Circle of Teleportation in the middle. On both ends across the circle are small storage rooms filled with crates and barrels. To the left is a staircase downstairs. To the right is a dining area with tables and chairs, the back of which includes a partially secluded kitchen with cauldrons and cooking supplies. The Revengers met Chef Drak here.
Dungeons: Directly downstairs of the top floor is a room that splits into two hallways. In both hallways are three large prison cells, across from which are deceased commoners held in chains. The party met Goron Skuljak here.
Corridors: A small set of corridors that lead to the ritual chamber. One room here seems to have been used for interrogation or torture, and is where the party encountered Drezvina and Skorvanos Dwendarian.
Ritual Chambers: A large chamber with a chasm lining the middle with poisonous green mist billowing out. At the far end was a large statue of a cobra with man-sized emerald eyes. A few side rooms and entrances to hallways are present. This is where a large battle between the Revengers and the cultists took place.
Side Door 1: Another dungeon room with four cells, complete with chains hanging from the ceiling. In the center on the floor is a metal grille built into the floor, where more green smoke escapes into the room.
Side Door 2: This door leads to a small stone terrace over a seemingly endless drop into what looked like a natural stone cave with no end in sight in any direction.