Returning with the head of a black dragon, one of the natural enemies of Rasvimi (the country you reside in) doesn’t get you the notoriety you would think it would. Sure, the dragon was small, but honestly – 4 weeks cooped up in an inn and not allowed to leave the city? Was this a reward, or just house arrest?
Finally, it looks like the city is ready to reward you. An invitation shows up from High Chancellor Aragol, inviting you to be rewarded for your service. It was delivered with an intricate red ribbon, which contained another secret message asking for a subsequent meeting with King Joff. You only know this because he told you about it afterwards. Nobody bothered to ever look at the ribbon. #disappointment
Aragol was nice. He gave you all a pretty ruby, and then told you to get out of town. He said it so politely though that you felt like thanking him afterwards. meeting with the king was way better though. He told you what the dragon you killed really meant. Things were about to get ugly. A thousand years ago, the black dragons developed the art of Hidecarving. It made them so powerful that a war soon broke out, with all the tribes of dragons vying for better and better Hidecarving techniques to become more powerful. The war shattered the very earth when tiamat herself sought to join the fray; The landsdrop was created when the earth shrank away rather than let her tread on it. Finally, after centuries of war, the leaders of the tribes made peace, and banned hidecarving. The art was lost, and the tribes became nations, with borders similar to what we see in Rasvimi today.
The dragon Blight bore evidence that she had been hidecarved. Aragol and the rest of the Council of Eight wanted to sweep this under the rug, lest it start panic. Joff was worried that if the war did come, it would be the human peoples of his realm who bore the brunt of it, and he wanted to find out everything he could in order to be able to protect them. So he sent you off to the lair of Malhavoc, one of the black Dragons who first discovered Hidecarving. Perhaps there you could find a book of his notes, describing what he knew.
Siding with Joff and the rest of the humans (and elves and dwarves and halflings) over the dragon blooded council was an easy decision, and soon you were off. You found the lair, invaded it and defeated the loizard men in residence there, and found the book of notes to return (in secret so that the Council was unaware) to Joff.