Vermulean

Vermulean was an druid who lived in the woods, outside a village in Icewind Dale, which was raided by the drow.

History
He was a humble old man who offered to enchant gemstones, free of charge. These enchanted gemstones could protect the owners from radiation that emanated from underground, and allowed them to see in the Underdark. He was knowledgeable about the ways of the drow and Menzoberranzan.

Once the companions finally reached Menzoberranzan, they sought to again make contact with the wise old man. Upon using the magics of Ssar Tarell, a portal was opened up where Vermulean identified the gems he originally gave them. It turned out that one of these was the Gem of Lolth sought by the houses of Menzoberranzan, as part of the Helm of Spiders.