“ 'AIEEEEE! YAI-YAI-YAIEEEEEE!'
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.”
“ A tribal society which lives on the harsh Northern Plains consider it dishonourable to slay an enemy without looking it full in the face. Any missile weapon is treated with derision and contempt, while rangers and other archers are denied entrance to the tribal villages.”
“ With a huge number of sacrificial victims, another realm long ago secretly bound a Prince of the land spirits, Iorstonn by name, thus ensuring the fertility, and improving the magical defences, of their realm. But binding that Prince to one spot has disrupted the weather and magical patterns (ley lines?) over half the continent. Things have become bad enough that a coalition has been formed to rectify the situation, once divinations have established the cause.
Your party is one of the teams assembled to do the rectification: find the binding object and steal it ('so that we can destroy it here in our realm, of course'...*) or destroy it over there. Presumably the Prince will be grateful to his rescuers and angry at the binders, but with a greater spirit like Iorstonn one can never be sure: such beings are 'tricksy'.
* Of course, the rulers of our realm might want to control Iorstonn for their own ends...”