This quest is not available in game.
Bring the Tiara of the Deep to Tabetha in Dustwallow Marsh.
Long ago I possessed a beautiful piece of jewelry, the Tiara of the Deep. And not only was it pretty--it held great power for those with the knowledge to use it.
So when word of the tiara reached the Hydromancer Velratha, she had to have it. She sent agents to my home and they stole it while I was away. The thieves!
I want my tiara back! Go to Zul'Farrak, the troll city in Tanaris, find Velratha and wrench the tiara from her. Return it to me and you'll earn my favor.