“ Somewhere along the line, someone very powerful lost their marbles. Literally. Possessing a marble allows incredible clarity of thought about a particular related subject.”
“ Throw in a handful of random customs - like women or men of a certain level of society being required to wear a veil or a pendant of some type.”
“ The PC's stumble upon a village strangely devoid of life and activity, but they get the feeling they're being watched.”