The Horde and Alliance band together for a final push into the Tomb of Sargeras
>Portals in the Tomb of Sargeras are ripping at Azeroth during the player's raid
>Kil'jaeden appears to be forcing his way into Azeroth through a massive portal in the Tomb
>Old God forces and Naga attack the tomb and raid near the end of the instance, and are more successful than the Alliance and Horde / players at stopping the demons
>Alliance and Horde / players were losing before the Old Ones and Naga showed up
>Old Ones are closing the portals and consuming their immense power and energy
>The Legion's advance is almost completely shut down by the Naga and Old Ones
>Kil'jaeden's massive portal and possible Kil'jaeden are consumed by a gigantic Faceless beast
>Horde and Alliance are trapped in the middle and poorly outmatched
>Players must escape the collapsing tomb a la Maiev in Warcraft III, sacrificing their artifact weapons' power along the way to feed to Old Ones / distract the Old Ones (has no effect on game play, it is assumed this is to explain away the artifacts in the following expansion)
>Old Ones and Naga are successful at harvesting the demons and their portals
>Nzoth has accumulated enough energy from eating L'Ghorek during Cataclysm, siphoning energy out of the Emerald Dream via the Nightmare, and now consuming demons and their immensely energy-rich portals to break free of its torpor and prison
>The Legion is halted once again, but Nzoth has played everyone perfectly. It implied Nzoth could tell the future because of corrupted/Infinite Nozdormu, and proceeded to use Kairoz to get Gul'dan to Azeroth to provide the necessary energy remaining to free itself.