For both Alliance and Horde, the first part of vanilla WoW was all about putting an end to Ragnaros, and uncovering and subsequently lopping off Onyxia's head for a delightful city decoration that was not at all likely to scare the pants off of any of Stormwind or Orgrimmar's children. Seriously, who thought dragon remains on a stake was a wise design choice? Regardless, while there were definitely giant foes to be beaten, if one dug a little deeper, there was some underlying story going on in vanilla, too.
The Alliance was busy getting back on its feet, and Warchief Thrall was busy trying to make nice with the Alliance. But even though Onyxia had been defeated, the king of Stormwind was still missing. And even though Ragnaros had been sent back to where he belonged, he was far from the only menace in Blackrock Mountain. And even though these problems were leaping up in the Eastern Kingdoms, there was something lurking in Kalimdor -- something far, far worse than problems with dragons and firelords.