Knowledge (religion) checks all round. Turns out that none of you has heard of Choth.
You follow the voice's instructions, taking the passageway to your right. The passageway turns one way, then another, but you continue along, ignoring the side passages. You make a last turn to the right and see a doorway to another room, light issuing forth from inside. As you look into the room, your eyes are immediately drawn to a huge stone statue of a dragon seated against the east wall. It rears up, wings spread, staring down at all in the room. Its eyes appear to be huge faceted blue gems, which catch and throw shimmering images of sapphire firelight across the room.
In front of the statue is a giant copper bowl filled with a leaping fire. The bowl is raised five feet off the ground on a stone block, and is eight feet high itself; it is untarnished and appears to be of beautiful construction.
Dozens of stone benches, some overturned, are arrayed before the dragon statue. Eight of them have the skeletal remains of lizard-like humanoids arranged on them.
Standing in front of the statue is a figure similar in shape to the undead lizard creatures you fought earlier. This figure is obviously alive, althought its scales have worn away in several places, revealing the gray skin beneath.
A skittering noise to your right attracts you attention, and you look round to see a large tangled mass of bones slowly moving towards you. It seems to be comprised of several of the lizard humanoid skeletons fused together to make a hideous, many legged creature. Three of the four skulls seated in the center of the fused bones turn to face you with an unpleasant scraping noise.
The lizard-man standing before the statue snaps something to the mass of bones, and it backs away from you slightly, bones grinding across the stone floor of the chamber.
The lizard-man faces you, cold eyes studying you all with interest.
"I am Tamalruk. I sssspoke with you at the doors to Hissss domain." The lizard-man speaks to you, his voice clearer now he is no longer speaking through several inches of copper. "Now we ssssee each other, face to face, assss you wissshed. We will bargain, yessss, and you will help me with the goblinssss, yesss."
He stares at you intently, waiting for you to speak.