Recently, I introduced the following Legend Lore to my PCs in my Eberron Campaign:
“Hatred born not of woman but man
Delved far below haughty man-made spire
He broke last wards on the Goblin plan
And sent the twisted to Dolurrh’s mire.
To Skull of the Wyrm his journey would span
And scour for secrets to Kharaam’s Fire
With Fire obtained his goal is to burn
The whole of mankind on Dolurrh’s Pyre.”
I designed it to give a warning, but tried to stay away from definite events that could be altered. Most of it has come to pass (a warforged has stolen a set of Goblin Lorediscs as well as an artifact to perpetrate something heinous with), except they don't yet know the particulars on the last couplet - it's what they're trying to find out now.