You start of as a level one human. The threat of the Defias has been dealt with; some still whisper that the treatment of the masons was unfair, some mumble about the corrupt nobles of Stormwind, but the Defias are no more. Elwynn Forest is a peaceful place now. The Kobold have been driving out of the mines, the Gnolls to the east have been eliminated after their leader, Hogger, was apprehended. Murlocks still linger in the east, farmers still need help against wolves, bears and overgrown boars, but life is peaceful. After completing initial training in Northshire Valley, you are sent to Goldshire to report to the Marshall there. With Elwynn Forest safe, the backyard of the human, nay, the Alliance capital safe, things are looking up for the human race. While in Goldshire, you see proud companies of Stormwinds best soldiers, marching this way or that. Redrige Mountains, Duskwood, Westfall; wherever humans live, soldiers march to liberate and defend.
The Marshall sends you to Westfall, and you jump on a caravan bringing supplies to Moonbrook. People have started moving back there, the Marshall tells you. There is iron to be found in the mines, iron that is much needed now. Huge rebuilding and rearming processes have been started, and Stormwind hungers for resources. But there are Kobolds in the mines. Many unemployed vagabonds in and around Stormwind jumped on the chance to get solid work at the mines, but they aren't warriors. That, the Marshall says, is where you come in.
You arrive in Sentinel Hill a level five [class], where there happens to be a marked this day. You talk to many farmers, who ask you to help with various issues. The lighthouse is overrun with Murlocks, some undead are harassing the eastern border, a few gnolls still reside in the mine to the north. You take some time to help them, and you deal with the Kobold problem in the Moonbrook mines. After reporting back to Sentinel Hill, you are sent back to Goldshire, now a proud level 10ish [class].
Back in Goldshire, the Marshall has already heard of your selfless deeds in service of the people. You're a man/woman who cares, and it impresses him. So much so, that he asks you to run a personal errand for him. A friend of him resides in the Tower of Azora, an old mage who once saved his life. This man hasn't sent word to Goldshire for some time. It's nothing unusual, the Marshall says, as the man is known to stay in the tower and have his servants do the same. Nonetheless, he asks you to check up on the old man, if only to ease his mind. You agree to the task, and travel east.
Arriving in the Tower, you are met with dead silence. The doors are closed, but open easily enough. When you enter, you are met with a gruesome sight. Dead men and women lay sprawling everywhere, but there is no signs of a fight. There is no blood, no broken bones, no marks of any kind. The candles are still burning though, and there's hot stew on a table. Suspecting that the stew is poisoned, you feed some to a few rats in a cage in the next room. Nothing happens.
You find eight bodies, but no old man. You couldn't very well report back to the Marshall that you did not even look for the old man, so you decide, against your better judgement, to ascend the stairs to what you assume to be the old mages study. As you near the door to the single room at the top of the tower, you hear faintly a mad chuckle from inside. You enter.
An old man laughs madly at you as you enter. He's sitting in a chair, but stands up to greet you. "Dead man walking", he cackles. You ask if he's okay, tells him what you saw downstairs, pleads with him to go with you to Goldshire. "It's far to late for that", the old man chuckles. "You thought he was dead. I thought he was dead. But he is not. The good part, maybe, but that's not all he was. Is! He is coming. They are coming.". Before your eyes, the old man turns to dust, and his empty robe falls to the ground. You don't know what to make of any of this, but you grab what seems to be the old mans diary and make travel back to Goldshire.
Approaching the village, you hear the sounds of battle. You rush to help, but is stopped from entering the village by a dying soldier. "You need not die here as well, young one", the soldier says. "Goldshire is lost. The king must know". You see dark forms in the village, shadows moving with grace and swinging dark swords at fleeing villagers. You elect to follow the soldiers advice, and make haste for Stormwind.
Honestly, I was gonna write more but it's getting late and you get the picture. What I'm thinking is that Karazhan was to good to be just discarded as is. A mad part of Medivh still lingers there, and is sending his undead minions to do his bidding; to locate Ateish; to discover the whereabouts of the treacherous Khadgar, and to force war upon the cowardly humans who betrayed him all those years ago.
You help defend Redridge mountains from Medivh, before you join the forces of Stormwind in retaking Duskwood. Finally you, side by side with the King, launch an assault on Deadwind Pass, where you fight your way to the foot of the tower Karazhan. You find the tower empty, but there's is movement in the crypt. At this point you'd be around level 25, and ready for a new dungeon: the Karazhan crypts. You fight your way through Medivhs most trusted lieutenants, before you join forces with Khadgar and Wrynn (and Thrall, of course), to silence the mad prophet for good.