“ 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.”
“ You wake in a pub and see that it's full of were creatures, and they're all staring at you with a scared look on their faces. As you continue on into the pub you look at your arm. You notice that your arm is covered in thick brown hair. As you continue on into the pub you look in a mirror, and staring back at you is a 7 foot werebear. As you continue into the pub people start to shy away form you. Once you go the bar you ask the weretigress that's the bartender and begin to ask her why everyone is shying away from you, and she begins ro tell you why.”
“ 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...”