Mah'rek gives the quest. He's sitting by the dungeon. I do believe you need to finish the Tomb of Storms to do it, and from my experiences in the dungeon, you want to finish it and get an extra spell for it. Mobs can put you in 1v3 situations, and the sidewalks aren't the best. Challenging dungeon, but it's best you finish DS before you try to solo it. Even then, my Ice is level 68 and I still have to go back and refill potions.
