The Siege of Orgrimmar will be the final stage of World of Warcraft: Mists of Pandaria. It will consist of both the Horde and the Alliance attacking the orcish capital city of Orgrimmar and taking down Warchief Garrosh Hellscream. Little is known about this event or the reason both factions will attack the city except for the fact that "Garrosh has become corrupted and has been doing some really nasty things beneath Orgrimmar