The Agents of Ioun recklessly followed Vesta through the mysterious portal and found themselves with an alien cave. Eventually, they figured out they had been transported somewhere in the Underdark. Hegh Dah was agitated, but quiet. The party was ambushed by a beholder and was nearly wiped out.
After They then discovered a river outside the cave complex and the water was frigid cold. After sailing down the river (no boat jokes please Leslie), the party discovered a massive walled domed structure and proceeded through the gates. Within the walls the party explored a beautiful wooded area, gardens and a fountain that geysered (its a word now) up and shook the area (no jokes Leslie or Mack please). They chanced upon a crying maiden, Asra, who told them the tale of her lost love.
The party continued onward and entered the palace of whitish marble-like stone. They were immediately greeted by a butler-type who extended the party every courtesy they ever needed. Vesta took advantage of the spa while they waited. The butler revealed the master of the domain :-) was Ellard, the missing High Priest of Ioun, and the object of their journey.