My name is Prince Stolas, of the Ars Goetia. I serve all of Hell in all ways of the stars and their prophecies. I should like to warn you all that I have looked into your stars, and though I have not been able to study them as intently as I would have liked, they are very similar to the stars in my universe. Enough that I was able to discern something vital to the Dunwich populace.
I am certain you all know that Dunwich is not like other towns. It's not even like it's supposed to be. There is something very large and something very old looming over it. A demon of monstrous proportions who lies dormant, for the moment, in a place beneath the town. Beneath, yes, but also in another space entirely. He is locked in an eternal battle with another demon who is even more monstrous in his actions.
There will come a time when these two giants will emerge, and you will be forced to reckon with their coming. There may not be any aftermath to contend with, but I wish you luck.