Thank you for paying heed to my fevered rants.  All along we had been trying to identify and destroy the Skettis chain of command; we had learned of three clerics known as the talonpriests, but we'd never seen them with our own two eyes.  Now we know why.$B$BTalk to Severin to obtain more of the elixir he discovered.  Use the elixir to find and kill the three talonpriests: Ishaal, Skizzik and Zellek.  They're rumored to dwell in Veil Ala'rak, near the eastern shore of Blackwind Lake.