It sounds like you're looking for a good story or campaign concept involving the Tome of Adventure Design , and you mentioned finding a PDF on PDFCoffee (a site that hosts various user-uploaded documents).
Roll result: An ancient, imprisoned entity being released by accident. tome of adventure design pdfcoffee
The truth: beneath the well lies a — a dormant extraplanar entity that feeds on sound and speech. A foolish relic-hunter broke a wax seal on a stone lid 200 feet down. Now the entity "drinks" voices. Each night, it reaches up through the dreams of the village. It sounds like you're looking for a good