The Watchtower

From the introduction:

When first constructed the Watchtower at Millerain guarded the edges of human settlement in the new world of Arborell, and for two centuries it served its purpose well. In these modern times it lies abandoned and desolate, the frontiers of the realms of Men found hundreds of leagues further to the north and west. It is however, no longer empty. Something has found a home within the crumbling battlements, spreading malice and malcontent upon the surrounding rural communities. Citizens have gone missing, and with their loss a pall has settled upon once peaceful settlements. Whatever lurks within the high tower wishes itself to remain hidden and undisturbed. It is your intention that this will not continue.