Ether, magical energy condensed into liquid form, is the fuel powering the magidustrial revolution on Ryngard.
Bringer of Oblivion, Reliever of Pain and Devourer of Souls - The Red Honey is the most popular narcoticum in Locastus, city of Mirrors
Even though the Gods struggle so, their achievements are temporary at best.
For all beings must dream, and within those dreams dwell the Dreamer.
Come then and succumb to the lord, come then and enter the realm of sleep.
Come then taste the nectar, made of the tears of the dreamer.
-The 5th verse in the Book of the Dreaming Cult
The local band of 'nasties' (goblins / orcs / whatever) lives in relative peace with the local population.
Along come the PCs and go through their usual heroic monster bashing routine, wiping out the nasties and pinching all their stuff, then continue on their way.
Problem is, they don't kill ALL he nasties. The survivors want revenge and, after spending a few months recovering, start to take it in their own inimitable style (which is not unlike that of the PCs come to think of it).
Next time the PCs are in the area they find themselves VERY unpopular with the townsfolk.