Nerundill caught hints, snippets of conversation. The rumors surrounded a book, a book of magnificent power. A book that contained the knowledge of the ancients. With every new tantalizing bit of information he heard, his resolve to possess this book increased.
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.