That’s no moon ...
Two young nobles, enmity between their families. Where have we seen this before?
When a local farmer discovers something at the bottom of his new well, the fate of the land will hang in the balance.
This mountain chain was once vast and impenetrable, but had the misfortune to named in the binding spell of a mighty demonic(godly?) being, namely that when the Great Mountains are forgotten, then shall it be free.
The heroes stop in a small town ready to restock their traveling supplies and feed for their animals. All of the villagers are starving, and there is no food to be had. If the PCs are quick witted, their noble steeds might be slaughtered for food.