“ A rich southern landowner once imported hundreds of thousands of spiders and distributed them along his long, tree-lined road. After a couple of days, when the spiders had make an incredible number of webs amongst the rows of trees, he spread fine gold and silver dust on them to create a spectacular shimmering view. (true story) It was for his daughter's wedding day.”
“ The Rhenn Plains are serene and peaceful, beautiful, and quiet as if nothing had ever had happened to it, hiding away it's violent present and past. During some time ago, the countries needed land to fight on, for they did not want war to come to their home, so they chose the Rhenn Plains, Armies met there and men died on the lands, so the land has been empty always. But now there has been set an outpost and they are beset by the goverments wanting to keep it free, will the soldiers of the barracks prevail, or fall trying?”
“ 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...”