Perceiving a direct concern on the flow of time, the bronze dragonflight has enlisted the help of large groups of adventurers to travel to the Battle at Mount Hyjal to support the defenders. The original battle was waged against the Burning Legion by a joint effort of Humans, Orcs, and Night Elves. The Legion's goal was to use the world tree to summon Sargeras and the rest of the Legion to Azeroth. His third-in-command, Archimonde, leads the assault to the world tree, Nordrassil, and the well of eternity at its roots. The coalition held off the legion long enough to unleash the energy of Nordrassil themselves, destroying Archimonde and the remainder of the legion forces.
Unlike other Caverns of Time instances, there is no evidence of the interference of the Infinite Dragonflight, just the usual Scourge opponents that would be expected. The zone plays out rather differently than the Hyjal Summit level at the end of Warcraft 3, which has the player outlast the Scourge for thirty minutes as the Night Elves, with support from the Human and Orc forces. In Old Hillsbrad, most characters receive the effect of Illusion:Human, but the characters on Hyjal seem to not care at all which race the players are, including the then-unknown Draenei.
One thing that has stayed true is that you must fight off waves of attackers. The zone itself is not large and there is very little travel since the trash mobs come to you. Each boss battle begins with a series of 8 trash waves of different mixes of the available Scourge enemies, arriving approximately every two minutes, or faster if your group clears the previous wave with time to spare. The first two bosses are fought in the Human base, the next two in the Orc base, and Archimonde's battle takes place near the World Tree by the Night Elf base. In each base, an iconic character is there to provide support, along with the nearby troops, and on the first four bosses, the raid officially wipes when that leader is killed.