Even before I had set about creating the world, I had decided that I was going to run a variation on the old trope adventure of rats in the cellar of the local inn. And with this I introduced a new race and deities into the world.
The twist that I decided to run with was that the rats had been feeding upon the mead that was being brewed in the mead hall in Joonsvyk. Over time the rats gained sentience from the mead and began to worship the brewer and his wife as gods. This brought into existence, Brennig the Mead-Father and Merin the Ale-Mother, and the race of sentient rats, the Ratkith. And the major source of conflict for the adventure, a cult based around a fallen Devil that loved wine, Milner. Along with this I introduced Joona, the namesake for the town as a deity. So with this I had the first four gods of the setting.
The adventure started off fairly well, the party didn’t groan that loudly when the owner of the mead hall asked them to pay for their meals and would give them a discount by helping them with an issue in his cellar. When they found the “rats” were tapping the pipes and not really stealing anything other than mead from the hall, I was presented with an issue that I hadn’t been prepared for.