An adventure for characters of 5th-7th level.
Lord Thomist frowns through his beard at your questions.
'The villages in the area are independent at the moment, but I have initiated discussions with them about swearing fealty to my banner. That is why it is crucial that this threat - whatever it is - be eliminated immediately. I can't afford to send troops away from my sworn lands, so I want you to go out under my banner as a visible symbol of my protection. All we know is what has been reported by travelers and verified by my men: Two villages have been attacked and everyone in them - men, women, children, and even livestock - have been killed. To the youngest child, they were decapitated, their heads flayed of all flesh and their skulls staked around the town. There are no surviving witnesses, but whatever killed them must have given very little warning. The bodies were found mostly in their beds. There seems to have been no sign of resistance or flight. If this is a mundane assault you have my command to slay all offenders. If it is some kind of vile sorcery you must root out the source and come to me for help if you cannot handle it yourselves.'
Thomist sighs suddenly and his shoulders slouch forward. 'We have no true leads to aid you. We have no idea what could do this, or where it will strike next. But it is evil and it must be stopped.'