The visiting delegation approached the grand entrance to the dwarven city of Roastone to continue the trade talks that started last season. The grand door that rose 30 feet in the air was closed tightly. The guards that would normally be expected at the entrance to greet, or repel, visitors were nowhere to be seen. A quick review of the area revealed a distinct lack of activity. From what the guides could tell, very little has occurred outside the mountain fortress in a long while.
As they continued to look, they found in hasty, yet recognizable Dwarven lettering the word "Troackoar" carved into the granite near the door. Looking on the other side a similar carving was found saying "Troack."
Normal customs of requesting entrance were tried daily in return for a stark, uncomfortable silence. The delegation had no means to enter so, after a week of patience and attempts to contact anybody inside Roastone, they left to report back to their king.
Another delegation was sent not too long after and had the same experience. Stories started to pass and tales told about the missing dwarves of Roastone. Tales varied from the dwarves isolating themselves from the world and are preparing for a major surprise attack against the land to stories that they were destroyed by any number of different things.
Eventually, dwarves from the the north sent a party to investigate the rumors. Through their knowledge of their kindred in Roastone, they were able to open the doors of the city. Those that heard the story of their entrance were told that the dwarves spent no more than an hour inside before they exited. They spent the next month moving in and out of the entrance in short bursts. At then end of the time they closed the doors and triggered something that sounded like the greatest thunder and shook the ground like an earthquake. Additionally the words "Troachoar" have been removed from the walls of the city of Roastone. The dwarves left and haven't returned.
No dwarf that went in have ever spoken to others that were willing to pass the story. The dwarves are keeping a great secret and refuse to share even the most vague of rumors. Questions will be answered, or ignored, by stoic silence.
This is, obviously, taken from the Mystery of the Roanoke Colony and the word, Croatoan, that was found there. I wrote it not so much for the above mystery, but for the plot ideas that could come from it.
The dwarves unleashed something from the depths. A chamber was breached and an entity was awakened. It is a creeping force of nature that nobody can escape and no known way to fight it. It is a force of random nature that holds no hatred or ill will, it just does what it's nature dictates when awakened. The most ancient and learned of the dwarves have knowledge of this entity. It seems that they have run across it a few times in their distant past.
It is a creature of chaos so there is no real trigger that sets it off except being the unfortunate ones that find it, however it normally isn't found in a common area. Generally in the most abandoned area, farthest reaches from human contact is where it might be found, if unlucky. It tends to hide in mountains though as it is the most comforting to it. It has no real needs, it just exists...and there might be more than one.
Once disturbed, it works by inhabiting the container itself, whether it be mountain, castle, forest, etc. It takes a defined space, invades it and doesn't allow any living being to escape it. Once that is accomplished, it fades without trace.
It ends up absorbing the person and all belongings into its force. Those that look from the outside would see the person disappear into the stone, into a tree, into a stone wall...whatever the container that the creature inhabited. The material it takes over doesn't seem to matter.
The sound that the disappearance makes is where the word Troachoar comes from. It is a windy, vague sound that isn't so much a word as it is a noise. If you extend the pronunciation of Troachoar in a windy raspy voice, that is a close approximation and one that these dwarves heard multiple times a day...the sound that takes their sanity.
Any attempt to write down an account of what is happening is subconsciously blocked as if their mind is blanked of what it intended to do. If they sit down to document it, the person will fall into a trance. Those few that are able to put word to paper are only able to write "Troachoar" and then fade again into a trance that few come out of. Those that watch the attempt of documentation are quickly convinced of the danger.
Over time, those that have access to a large amount of obtuse documents may have found multiple incidents of the word "Troachoar" found in association with mass disappearances. From ships found abandoned floating the sea with the last word in the log book being "Troachoar" to forests or outposts suddenly without any life except a random carving of "Troachoar" in the bark of a tree. Troachoar is not unheard of but it is very rare. Especially rare to even find evidence of the events.
If investigated, there will be no bodies anywhere. Whatever they left behind will remain intact and untouched. The entity will not leave until every living animal is absorbed. The place is perfectly safe to explore if they dare.
The dwarves will seal the city because it has happened to them before. They don't know what it is but they fear angering it again. They do not speak of it for fear of calling it back and they don't bother any location it has destroyed. They feel it is cursed and can only bring evil upon any that disrupt the sanctity that it has created.
Thoughts on the creature:
Not sure if I have any really. I have it being completely random. It will generally exist in a calm state in a never, or rarely, traveled area. Amidst the farthest unexplored oceans, deepest caverns or thickest woods. It has no interest in fauna and just exists in an unaging state. Once disturbed it is like breaking a bubble, the entity expands and inhabits whatever container-like area is it released in and fills it. Then it starts working inward absorbing everything in its path. It might be that it requires the life force to reshape its "bubble" to once again remain in stasis and peace, which is its natural state. Once it regains its solidity it pops out of that area and appears somewhere else to just be and exist.
They mined into something that would resemble extreme radiation sickness nowadays minus the vomiting (the fortitude of the dwarves can resist this...didn't want the puke everywhere is my main purpose). The dwarves started losing their beards and then the rest of their hair. The elderly died quickly as the young started to get weak. This all happened fairly quickly, maybe a couple weeks.
So they closed off their kingdom to protect their pride, and hopefully, the world from what they discovered. For them, Troackoar is an ancient legend that is rarely spoke of by the dwarves that describes this exact ailment. It is kept secret for dwarvern pride and few know of it. It is even kept secret from most dwarves. Those sages could search the documented knowledge of the past and couple, perhaps, find some small clues to other dwarven kingdoms that have simply disappeared
The great treasures of the city do remain for those foolish enough to enter. Perhaps some magic could protect those that could even find a way in...perhaps not. There might even be a race that is immune to whatever the dwarves dug up. No dwarves have ever attempted or requested assistance to find out.
The dwarf that knew of the ailment (or was told by an elder and was blindly obeying the order to carve the message) fell weak by the time he started the carving of second word. He either died outside and was brought in by others or quit before the weakness fully took him and he couldn't close the door.
If investigated, there would be bones everywhere with all items and valuable in the normal places. Perhaps many would gather in the great hall in full battle rattle to be amongst friends in a final show of strength and give a final worship to their dwarven god.
Secondary thought with this: Could even make a certain family of dwarf affected differently from the poisoned source that was uncovered. They could be given greater strength, madness and ability to heal very quickly. This combined with the illness to the normal dwarfs would enable a small amount of demonized dwarves to kill indiscrimately.