Nature Leseul

Random townsperson: There are invisible ghosts in town! Put on these magic goggles so you can see them and kill them for us.
Player: Okay!

Invisible ghost: Arrgh! You're making our master, Big Evil Guy, really angry!

Random townsperson: Big Evil Guy??? ZOMG! He's supposed to be dead! Go talk to this other mysterious ghost at the Altar of Evilness, far away and where no one ever goes, and see if he knows anything.
Player: Cool, a plot!

Random NPC involved in some other quest: (Shouting to the entire zone) LOL I'M BEING STEALTHY! KILL ALL THE MOBS THAT SEE ME, SO ULTIMATE EVIL GUY WON'T SEE ME BEING STEALTHY! OH AND FYI, I'M REALLY A TRAITOR, SO DON'T BE SURPRISED WHEN YOU DO THIS QUEST YOURSELF LATER AND FIND THAT OUT!

Big Evil Guy: (Appearing on the path to the Altar of Evilness) Hi! Someone else just finished the quest and spawned me. Guess I'm alive after all, huh? (Wanders off)

Player: (Arrives at the Altar of Evilness, far away and where no one ever goes, and peers through a crowd of other players waiting for Mysterious Ghost to spawn)
Mysterious Ghost: (Respawns) Hi. (Assumes mysterious voice) Yess, Player... I know of Big Evil Guy... But before I tell you what I know, you must bring me the Cuisinart of Misfortune, and twelve Vaguely Purplish Rocks, and—
Other player: (Talks to Mysterious Ghost and finishes a later quest in the chain before it can finish giving the quest)
Mysterious Ghost: Blaaargh!! Now, Other Player, I pwn your soul! (Reveals true form!)
Other player: OMGWTF! It's Big Evil Guy! What an unexpected plot twist!
Big Evil Guy: BLAAAARGH!!! (Spends ten minutes fighting some other random NPC and despawns)
Player: (Taps foot, waiting for Mysterious Ghost to respawn)

Mysterious Ghost: (Respawns) Yess, Player... I know of Big Evil Guy... But—
Other other player: (Talks to the ghost)
Mysterious Ghost: Blaaargh!! Now, Other Other Player, I pwn your soul! (Reveals true form!)
Other other player: OMGWTF! It's Big Evil Guy! I never saw that coming!
Player: Sigh. (Logs out)