Hello MMOwned!
Okay this is an exploit for this quest: What Book? I Don't See Any Book. - Quest - World of Warcraft
First, you need a flying mount. So if you don't have one, this won't work.
Now what you do is you get this quest and then go talk to the guy you need to kill and start the event, after that just mount up and fly a couple of yards up so he can't reach you. Wait about 15-30 seconds and he will no longer be aggressive and you will get the objective and can then turn it in.
Enjoy!,
Insignia96!
PS: I searched this and couldnt find any reposts, but if there is i am sorry. :P