There is a plague in the fortress.
Not a sickness among the dwarves. In fact, nothing is sick at all. The plague is not a spreading disease - it is a kind of spreading
wrongness that afflicts the very earth that the dwarves walk upon. As far as the game itself is concerned, this is obviously some kind of bug, but within the context of this story, the saga of Weatherwires, this plague is the darkest of omens, the manifestation of the will of an angry and vengeful god of murder and death.
This omen has been present in the fort for some time now, staring me in the face. For how long, I cannot say for sure, but I have just noticed it. Take a close look at the screenshot I posted earlier today:
Do you see it? Look closer. The color is a little off, so it might be difficult, but it's there. If you can't find it, I've pointed it out with the cursor in this picture.
Here, in the heart of the dome, grows a patch of green grass. Indeed, two patches (you can see it in between the two dwarves between the stairs). In any other context, this might be a welcome curiosity, but for the dwarves of Weatherwires, who have forsaken the surface, green grass is a horrific sight. Not only does it remind them of the curses of the world above that drove them into the deeps forever, but it calls to mind an ancient myth, a deity of the Merchant of Echoing who, unlike the various other well-loved and worshipped gods, has no representation in the temple ring which dominates the dome.
Baros Buriedplagues, god of light and day, but also of murder, death, and rebirth, one of two gods not worshipped by the dwarves of Weatherwires. The surface world is his domain alone, and he has been forsaken along with it. Any dwarf who sees a patch of grass growing in the dome - the darkened, secluded sanctuary which has been sealed away from the surface by fire and stone - could not fail to be reminded of Baros, and the fact that he must view the lower fortress itself as the greatest of profanities. He has made his mark upon the Weatherwires:
...and as they pass the surface vegetation on their daily errands, the dwarves slowly realize the nature of their misfortunes, and the identity of their malefactor. In 135, the duke Kogsak Murdershot drew up the plans for the excavation of a great grotto beneath the earth, a utopia for dwarves and an escape from the lighted surface world.
It was in 135, too, that the great tantrum spiral erupted. For five years, dwarves died at the hands of their kinsmen, and the duke himself went mad. Determined to carry out her husband's plan, Domas Tickcities oversaw the excavation of the dome. Two decades after digging began, the fort was stricken with infertility. During the flooding, various mechanical issues sought to slow the pumps or cease them entirely. Now, a score of ghosts haunt the fortress, patches of darkness-defying grass grow in the deeps, and one name is on the lips of all:
Baros Buriedplagues.