So I realized my Fort's been at siege for a decade now, still ongoing.

A decade of siege. 8 dead necromancers, 3 captured. 233 undead linked to one cage, more captured corpses are to be placed. Their numbers can be increased with the possible harvesting of the raven stockpile. Zero Justifying Dwarven casualties.
Go home Necros, this Fortress will never break.
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Silentthunders's had a decade of war now! Just killed off a fresh new wave of undead elf corpses. The siege still continues. I'm still hoping on one last final great siege with all the tower's necromancers in plain view, so that it can all finally come to an end one way or another. The last attack had 51 Elf corpses, the least powerful of them yet. As they increase in frequency, so too does the scale of the attack decrease. Has my local tower exhausted its Elfpower, and are these the few stragglers moping their way to their second deaths, or the precursor to a tempest?
Where are the rest of my Necromancers? They nearly overran my Fortress with just three, and yet they have wasted 6 trying to sneak in. What's worse is that the decade of no trade has really impacted the Fort hard. Where booze stocks once sat at 11,000, now they lie at just above 5400.
On another note, do necromancer sieges also block access for other sieges, namely that of goblins? Because before the rotten Elf corpses showed up there were goblin ambushes and kobold thieves - now, only silence.
I imagine along with the caravans, my Fortress has become isolated from the world, surrounded by Elf corpses. Without their Necromancer masters to guide them, they merely infest the forests, waiting until hunger drives them to feast on merchants, siegers, thieves and Dwarves, fleeing away from the occasional rampaging Megabeast.
When Splint made this statement:
A forest infested with undead elves sounds like it'd make for a good backdrop in a fantasy story actually...
And it made me realize what the connection between zombie Elves, necromancers and evil forests was.
Here is how I best explain what Dwarf Fortress has just created:
Engraved in the wallThe forest is considered cursed by locals. It rains blood and all the trees are dead. The corpses rise when they are left in those forests, and the corpses seek the living to spread their death. Occasionally corpses leave the cursed soil and attack local towns and settlements, but in doing so gain the risk of dying a permanent death.
For everything that stays within the Forest, all that is dead stays living forever.
Surrounded by these forests, enclosed within a Mountain pass a Dwarf Fortress stands.
The curse touches this Fortress, just a tiny pinprick - and so the Forest vies with this construction for supremacy. Unkind rolling clouds of black ravens with claws and maws that tear the skin and flay the muscle of everything without shelter scour the ground from the skies with the same vigor as they attack, even as a volley of bolts is made airborne against the approaching storms.
Dwarven merchants make their way to this Fortress, passage made safe by the vigilance of the Mothers and Fathers of Silentthunders. They see the masterly-crafted statues, the death-dealing weapons and the strength of the Metropolis builders within. This is a good Fortress.
Human merchants make their way to this Fortress, hired mercenaries guarding those opportunistic fellows. They see the bright metal gilding, travel the metal-wrought roads and see the chaotic sprawl of workshops with Dwarves within, producing goods with no peerage. This Fortress must be divine.
Elf merchants make their way to this Fortress, safe traveling with their animal companions - Giant Desert Scorpions protect these visitors. They see the stony surface and think of the lost forest, they lament. But they also see the tapestries and the vestments so skillfully weaved and sewn that it put their own wares to shame, and when the Dwarves show them the sanctuary with the Old Willow by the brook, they think perhaps these Dwarves are different.
Kobolds sneak their way to this Fortress. It reminds them of a cave, but different. Not rough. Kobolds know there are gems inside. They see.
Goblin raiders make their way to this Fortress, they sneak their way past the cursed Forest's dangers. The walls they see do not appear so high, but the Fortress is large and even the Fortifications betray no secrets within, those open windows covered with shutters, portals and doors. They see only defences and Dwarves. They attack one Dwarf, and are surprised to see this Dwarf fend off their colleagues with a devilishly sharp spear. They flee when they hear the sound of more Dwarves coming. They see the fine cloaks hiding the shining steel - there is something valuable worth defending in this Fortress.
Necromancers make their way to this Fortress.
They bring with them hundreds upon hundreds of Elf corpses to this Fortress. They march and they fight, row upon row of terrified Dwarves carrying whatever weapons are at hand vaulting along the walls and charging the massed ranks of corpses. Broken and with their Necromancer vanguard destroyed, the Necromancers plan.
They scout, they search and they do it themselves. Corpses cannot sneak as good as they, who have unlocked the secrets of life and death itself.
They do not hear the gates close behind them.
...
Many years later, the Necromancers who fought the Fortress lost and died. But the Elf corpses remained, waiting for their masters to return.
Year after year, waiting for them to return.
Without their masters, they do not die forever. The forest keeps them animated. Elves twitch, swaying and standing on spot.
Some begin to... Feel? They look for their masters. They feel lost.
"THE DEAD WALK! HIDE WHILE YOU STILL CAN! SEND ALL MARKSDWARF UNITS TO THE WALLS! WITHDRAW ALL GUARDS TO THE COURTYARDS, AXELORDS AND HAMMERDWARVES TO THE COURTYARD!"
They walk towards the noise.
They are hit by something cold. They feel cold.
For the first time in a century they try to breath a sharp intake of air through broken lungs, surprised that they feel; surprised that they close their eyes.
...
One Necromancer sits in the darkness. She wonders if this is the Dwarves' way of a joke.
She has sat there for half a decade, it feels like more. She sits around so many corpses, she wants to make them live. But she can't, she cannot make the gestures needed to do so. She won't die here, she learned the secrets of life and death.
She thinks so anyways.
They fed Zuglar to a giant Scorpion and Asmel fell into a Winter's pond. Secrets did not save them.
She wonders if she has failed her children, if she cannot save them.
She sees the Dwarves close the door behind them as they finish hauling a new carcass into the pile.
...
The Dwarves stood around one moving Elf head. It twitched, still moving. It had been knocked clean off by a steel bolt, easily severing the frigid and worn tendons keeping it on its body. It moved towards the Dwarves surrounding it. Where once panicked workers stood carrying all manners of equipment of various metals, bones and woods - now elite Lords and heroes of war, industry, family and discovery stood clothed in brilliant raiment and impossibly strong armour, perfectly wrought to deflect the blade of any ordinary foe.
The head twitched again. Was it trying to move? Was it trying to bite at their shining toes? To Kivish, small child Kivish, it looked like the head was trying to speak. It had no voice.
Nil Erith, the chief hammerer and Professor on defence against the supernatural scolded Kivish, picking up the cadaver's head by the end of Akrul's spear.
"Don't be scared small one, this is no bogeyman, though it may be a night creature. They are simple-minded creatures, they know only the basest of instincts. They can't hurt you, not as long as we have weapons in our hands." Erith said, waving the head around.
Kivish was going to say he wasn't staring because he was scared, but by then Erith had already split the Elf's skull into shattered pieces beneath his warhammer.
...
The elf wasn't hungry anymore. He thought he was, but he really wasn't. The forest reminded him of something.
There was another forest, another time.
There was another time.
Looking down, he realized he was naked. His copper skin was frayed with patches of black, where disused organs imitated their once useful state.
The other Elves stopped fidgeting. They looked at him.
He looked back at them.
...
The world had heard the tales. The goblins spoke of a vast clearing in the spidery forest, with a legendary outpost guarding a path to the center of the Earth - filled with riches beyond anything ever witnessed. The Elves on their journey spoke to the assembled tribes of wonders not made by nature, legendary craftsdwarves who lived above ground in stone halls, carved not out of a mountain, but built from many smooth blocks and within it a sacred grove protected by old trees that keep the influence of the cursed lands away. Dwarven merchants boasted away that they had seen such wonders, of monumental constructs like battleaxes the size of a great stalactite looming over a bloody archway. The last outpost liaison of Eshomamud hushed the drinking halls with the reminder that the Fortress had not been heard from in many years.
Rich human merchants drank from each other's wares, showing off rings, ropes and strange mechanisms, their tales of these exotic trinkets' origins seemingly so unbelievable that it could only ever come from the tongue of an inebriated merchant. These rumours however, did prick the ears of a few odd individuals who by chance had been drinking beneath that same establishment's roof.
Why so few people attempted to visit this Fortress, many have their reasons.
Some say the Dwarves are selfish, who in their greed have angered the gods and cursed them to live forever in their halls alone. Others say that beneath the walls, everything is not as it seems and indescribable horrors lurk, hunting from the dark depths beyond the Earth and beyond the Universe of Forever. Most just say that no such Fortress even exists, and that it's just a fantastic but otherwise unremarkable story to tell children of to make them dream.
Most telling of all, for the true reasons few venture to Eshomamud, is perhaps best seen from the Kobolds; those who spoke not at all of this Fortress, for they had no language to speak with.
If you were to find their caves and sneak past their myriad guards amidst their many stolen treasures, you might find a crude engraving on the wall. The specifics vary from cave to cave, but the skilled historian would find they all share some things in common.
The first is the Mountain that reaches the sky, standing atop the depths of some tunnel going deep below even the caverns. It is adorned with spikes and piles of radiant scribbles, painted many colours.
The second more oddly enough, are who stand outside the walls. These intruding figures are obscured from the mountain, and on close inspection look quite similar to one another, taking into account the skill of the Kobold who engraved it. Short, squat figures with sharp, ugly lines accentuating what looks like an attempt to convey muscle, with red hair and shaded skin painted in various dried ichors, and to make things more enigmatic these intruders do not look at all like the Dwarves engraved on the walls.
The heads of these intruders are most often enlarged by the Kobold artisans, with humourously large splayed out ears coupled with grave wounds showing these to be some peculiar demon or living Elf corpse.
They are depicted the same way on every engraving.
...
"The Elves are labouring."