The Insidious Library of Niltras

From the introduction:

Many ages ago the evil sorcerer Niltras, bent on attaining mastery of the Dark Arts, accumulated a vast wealth of wicked knowledge and built a library of insidious lore. His final step before ultimate malevolence was to transform himself into an immortal vampire. To guard his coffin and collections he built a tower far to the north where the nights are long and the days are short, then spread his shadow across the forest and hamlet of Elms Green, transforming the townsfolk into werewolves. Then one day Niltras simply disappeared, never to be heard from again. To this day no one knows why.