You bring the scrap of cloth and the propaganda piece to the people by the wagon. From closeup, you can see their Stormwind investigator tabards. "Do any of you know anything about these?" you ask. One of the investigators, the most smartly-dressed of them, seems disinterested. Another of the investigators seems more interested. "Might be worth a look, Laine," says the investigator. Seems he can't look into this on his own; probably a subordinate of this Laine. The smartly-dressed investigator, still disinterested, stands up, takes your propaganda, flips it over, and tosses it aside. You grab it as it starts to flutter away. Looks like Laine doesn't see much worth in what you've found. "Nice find, rookie," says Laine. "I think I have a stack of these back on my desk in Stormwind City. We're basically at square one here. All we know is...someone who likes to write fiction about the past sent the Furlbrows a letter. Looks like we got ourselves a real history...mystery."
Ask what Laine thinks you should do. Maybe he actually has an idea. Check for clues on your own. Laine seems stumped. You can do better. Ask if anyone here knows someone who knows about this past that the "fiction" might be about. That might give a clue.