This quest is not available in game.
Travel to Blackrock Spire and destroy War Master Voone, Highlord Omokk, and Overlord Wyrmthalak.
This information fills in the gaps to our otherwise impeccable intelligence of Blackrock Spire.
The attack must be decisive, <name>.
First their war master, the troll Voone, must be destroyed. Without his battle plans, the Blackrock orcs will be thrown into chaos.
You must then take out the ogre Highlord, Omokk. The cowardly ogres of Blackrock are powerless without his leadership.
Lastly, the overlord of the citadel: Wyrmthalak. With Wyrmthalak dead, their central command unit is without a conduit.