“ 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...”
“ In one region of a forest, all of the trees are identical, down to the leaves and the twigs. If the PCs carve something into one of the trees, it could mystically propigate until it covered all of the trees, or could vanish since it was not carved into the one true tree.”
“ It is said by the village gray beards Of Breen, that the band of human exiles who founded their prosperous farming settelment almost a century ago,had to fight a long,savage struggle with the original inhabitants of the fertile valley;monstrous trolls that saw the new arrivals as meals, rather than as potential neighbours.After 5 long years, the humans with their superior steel weapons, drove the troll tribe into the bleak highlands and hills sourounding the valley.But as time passed, the old tale begun to become legend, rather than history and is regarded by most, as a mere story used by parents to frighten disobediant children.And yet the village leaders have always forbidden their people from wandering the hills....”
