The Nameless Spellcaster
There was someone. Small — probably a gnome. A spellcaster of some kind. He was there early on, Session 1 at least, and some of Session 2 — the timeline is harder to pin down than it should be. He had a potion in his pack. Comprehension, or something like it.
When Rimetalon came through the roof of the chamber, he was buried under the falling rock. The party retrieved his potion. His body was not recovered.
Most of them don’t think about him much anymore. When they try, the details are harder to place than they should be. That’s probably normal. There was a lot happening.