Dawn Fire has some lovely amber stones that he wishes to sell to Princess Luna. She wants one more, larger one to be the center piece of a necklace. Getting it has a "Minor" obstacle!
Prance and Equestria are not on good terms. Last Hearthwarming Prance attempted an invasion through the Corbiestep pass in northern Equestria. They were stopped by last heir of County Corbiestep, who to the background of her family killed, the castle afire and insufficient arms or troops, managed to rout the invaders.
Now, going to the source of the amber, in the Weirdwood of northern Prance, has a different sort of price than simply money . . .