Ye Blue Bookes of danjerus andde koruptynge knowlidge, the finalle tombe of Five Great Wizzards.
A very ornate and very old looking spell book. Chock full of spells, most of which are unreadable by any magic user. The ones that can be read, unfortunately, don’t have the affect the mage is looking for.
A village where everyone goes blind sometime during puberty. What could be causing this? Perhaps something in their diet. Or some malignant gene. How would an entire village where only young childen can see function?