This quest must be completed by all wishing to become Shaman in Freeport between the level of 18 and 19. You will not be able to level to 20 until you have completed this quest. It is given by Mizzog the Sighted in North Freeport.
Mizzog will ask you to kill the following monsters in the Wailing Caves:
- Shin'Ree Aggressor
- Shin'Ree Spiritist
- Essence of Shin'Ree
Return to Mizzog after completing this task and you will be asked to kill the High Priest Gloomcry. He can be found in an instanced version of the Wailing Caves in the Commonlands. Kill him to complete the quest.