This is a newly redesigned Heroic Adventure and can be completed somewhat faster then the older versions.
This task starts in Demiplane of Decay with Karth Punox.
The keyword for him is assistance
The actual task takes place is Crypt of Decay. So head north past the Mayors office and click the crypt to zone in.
The task steps vary each time.
This mission was all done by killing the rats in the north cave on the top floor.
Narogg' s Place 