A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.
Unbeknownest to the character, he is in the royal bllodline. Suddenly the majority of royals fall ill and die, and the hero is left with the crown, but no experience or idea of what to do.
A Deity of some sort has unleashed a plague of bookworms or something like that in the area. Almost all spellbooks are destroyed, along with bardic and historical books.
Loud war-screams shatter the silence of the forest. The party, scrambling quickly over the thick forest floor, are ambushed by savage elves, dropping down from the trees and rock outcroppings. Their hair is cropped into mohawks and their arms are striped with tattoos.
They attack, and scalp unfortunate victims.