A Dirty Job
This quest is given when the player speaks to Tarkleigh after completing the quest Mercy Mission or the player enters the Fetid Pool.
The objective is to defeat Kadavrus the Defiler, a unique Necromancer. Once you have defeated Kadavrus, you must eliminate the remaining undead in the area.
Once you have done so, return to the Lioneye's Watch and speak to Tarkleigh to receive a Book of Regrets that grants two passive refund points when read.
This quest is completely optional, and not required to proceed through the act.