The story of Mansacks, the cursed crater.
The site my Dwarves embarked to looked pretty good. Lots of wood, a river, and a dozen-or-so tiles from it a lava pool surrounded on three sides by a collar of clay cliffs. At first I was worried about stone, but after digging into the cliffs I quickly found layers of microcline and granite. I carved a 3-square entrance tunnel into the cliff, ending with a common area dug exclusively in microcline. In the same area I placed a trade depot made entirely out of microcline. I called this place the azure chamber. My dwarves were carrying food inside one of the newly-dug rooms when they came.
At first it was just one fire imp. He jumped my metalsmith and chased him into the woods. One fireball, second fireball, third fireball and the metalsmith was dead. Unfortunately one of them missed and set fire to the nearby trees. The fire started spreading rapidly and the remaining dwarves fought to save the supplies still in the wagon, which was placed in the woods on the other side of the map. They braved the fiery front carrying barrels of food and booze until the wagon itself caught fire. In the last pulse of bravery and dedication to survival of the settlement, the mason grabbed a barrel from the flaming wagon and decided to carry it to the camp. His senses clouded by the smoke he did not realize the barrel already caught fire. He burned down halfway before his destination.
Lured by the heat on the surface three more imps jumped out of the lava pool. They made short work of the remaining dwarves save two, but chasing their prey they got lost in the burned-down woods.
The two survivors decided to keep the site running until immigrants arrived, so they could relay the terrible story to the mountainhomes (they wouldn't survive the journey being very low on food). The two were: a miner and an animal caretaker/trainer. Apparently the caretaker lost his mind from the deaths of his companions. He took care of animals for the rest of his life, not minding his thirst or hunger. He eventually died of thirst in the azure chamber, surrounded by animals totally oblivious to his corpse.
The miner realized the microcline must have been cursed, as after unearthing it the catastrophe started. He began to mine a channel of lava to prevent any further tries of settling in the cliffs beyond the lava pool. He soon ran out of booze and was left with a single barrel of meat. But he still carried on digging the lava channels to seal of the cursed room.
Eventually autumn arrived, and with it a wave of settlers. Coming near the site the first thing they saw was a single dwarf mining a channel of lava. He looked tired and starving. Before they managed to get to him he lost consciousness and fell into the channel he dug dieing in lava. He did not relay the story of the cursed chamber to the newcomers.
The settlers found no other survivors, only rotten corpses and charred bones. Thinking that goblins slaughtered everyone, they returned to the mountainhomes, so a military force could be mustered to reclaim the site.
During the spring three squads of dwarves arrived to reclaim the site of Mansacks. They were all long-time friends, and were ready to settle in the place after repelling whatever threat it presented.
At first they encountered no resistance, so they started carrying supplies into the halls. When they entered the azure chamber the only thing they found was a trade outpost. And blood. Lots of blood. Everywhere in the room there were corpses of animals: dogs, cows, horses. The blue walls of the room and the trade depot were spattered with their blood. Did the goblins do this? Suddenly from unfinished granite living area a fire man attacked from his ambush. One of the squads armed themselves and attacked him. The demon ripped the lower body of the first soldier off from the rest, while other squad members clubbed him to death with their hammers. The injured dwarf died soon from bleeding to death.
The rest of dwarves eventually started production of furniture in the fortress, but for some reason none of them wanted to clean the animal corpses in the azure hall (later I realized they along with all the stones were set to forbidden, this was the first time I tried reclaiming a fortress). Soon the imps arrived again and with them another fire man. One of the squads, armed with crossbows made quick work of the imps, but the fire man kept running. The fights set off another massive forest fire, but fortunately all supplies were already inside. When the squad finally cornered the fire man, the beast put up a good fight heavily wounding two dwarves before finally turning into a mound of ash. One of them was transported to the barracks, the other to one of the newly-furnished rooms.
But the curse of azure chamber does not let it's victims get away. The rotting animal corpses and death of a friend started to drive the dwarves insane. One of the tantrumers destroyed the trade depot, another destroyed carpenter's workshop throwing beds around the chamber. One of them eventually went berserk. I activated a squad of dwarves who had the least things to do, but unfortunately the squad consisted of only 4 soldiers now. Two of them were bedridden from injuries, one was asleep in the barracks and the last one was attacked by the berserker after carrying water to the bedridden dwarf in the room area. The berserker ripped the soldier's throat out, but somehow in his madness managed to keep him alive long enough that the soldier bled to death rather than suffocating. This all happened in the hallway of the room area, and other dwarves were afraid to bring water to the bedridden soldier, so he died from thirst, as did the berserker.
Death of those three dwarves made another one went berserk. Blaming this on the squad who did nothing to stop the previous berserker he burst into barracks. Throwing only a quick glance at the injured soldier, he quickly attacked the sleeping one spraying blood across the walls. As with the previous three they all died of thirst and bleeding. The remaining dwarves started going mad. Two became babbling wrecks. One threw himself into the lava, another undressed in the azure chamber and was quickly killed by a microcline stone thrown his way.
I ordered the last sane dwarf to build a microcline wall at the entrance to the cursed settlement. The brave farmer-turned-mason, walled himself and the remaining rampaging dwarves inside, forever sealing the madness of the cursed microcline chamber from the outside world.
No word reached the mountainhomes about the fate of Mansacks, but the scouts reported seeing no hostile armies in the area, meaning that it was not the invaders that stopped the settlement of the place. Fearing further losses the king forbid making settlements there, and ordered the change of description of the area to "terrifying".