This quest is not available in game.
Enter Zul'Aman and visit Halazzi's Chamber, Jan'alai's Platform, and Akil'zon's Platform. Report the details of those areas to Budd, at his camp in the Ghostlands.
How did those fools fail? I told them to be careful - even gave them disguises to help them blend in. Ahh, well. The bright side of their failure is that this opportunity falls to you.
Succeed, and you'll be well on your way to joining my crew and sharing in the immeasurable fame that will soon be mine. Not that I need any more, mind you.
There are yet a few portions of my map that require further exploration before our excavation can be initiated....