This quest is not available in game.
Wait for Wrathion to contact you.
[To Be Continued in Patch 5.2...]
<name>, I have never heard of this Council of the Black Harvest. However, the fact that they are interested in my father's power concerns me greatly.
However, I do have... contacts, who may be able to help us track them down. Most of my agents are preoccupied with the Alliance and Horde battle in Krasarang. Once that has settled down, I will help you.
For now, feel free to leave the Naaru relic in my protection, or not - just don't end up dead somewhere at the bottom of a swamp.