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.
“ Adventurers are to capture an unknown monster for examination (for a sage or wizard) but they are themselves captured by the monsters, and researched.”
“ A demagogue imimates the warrior-king or military officer of a long past age-his followers have the uniforms and weapons of that past time and are a dangerous group.”
“ The small coastal town of Her-Desh has vanished - the bay where it once stood is now unspoiled countryside. Moreover, the locals claim to have never heard of the place. Perhaps the Priests of the local Temple can shed some light on the mystery...”