Find and seal a Major Life Rift in Stillmoor. You must complete this rift past stage six to obtain quest credit.
After sealing the rift go to (1900,3463) and use the Dowsing rod. Now follow the trail to (1600,3425). Slay the four Priestess of Nechtan. Now Nechtan will aggro, he is a level 52 elite so bring friends (like the group who helped you seal the Major Life Rift).