There are some types of evil that are not easily recognizable as such. Much like the mountain-top ascetic or the cloistered saint, there is no obvious sign of the darkness that lurks inside Vodai.
A family of semi-retired doomsday cultists, just trying to live a quiet life while tending an apple orchard in the country. Except with complications.
The secret for immortality has been discovered by an eccentric wizard/mad scientist. Its found you need to reapply once a month. As people stop dying, and the birth rate increases exponentially, people are forced into homelessness, because of the need for food reamins the same, and food is not being produced fast enough to feed the undying population. The PCs have to find the creator and kill him, and destroy production, to save the world from undying, unending torture from hungryness.