The Trouble Below

We commend your zeal in wanting to help out here in Ogri'la, $c. However, we have a favor to ask of you before we can accept your assistance.$B$BDown below our brethren are enslaved to the Sons of Gruul. Please, speak with Mog'dorg the Wizened, who is leading an ogre resistance against their gronn masters.$B$BSeek him out atop the tower on the eastern side of the Circle of Blood arena.