Ah. Yeah, that happened in Deathgate too.
I spent so much time reforming the layout of the base and defences in hell, set up a proper front gate with 300 masterwork adamantine spikes with masterwork mechanisms, a functioning archery range with a set of fortifications and moving the entirety of the military from the surface to hell. Trying it out, I killed 4 demons with only one casualty (to this day is the best kill to death ratio in the entire fortress). I just didn't get enough time to link up all of the spikes, so I set out specific instructions to do it.
The first thing the next guy does is build a dining room/statue garden outside my front gate, getting like 20 dwarfs killed. He ends up building in the way of my fortifications, rendering them useless. Also forgets to link up the spikes, so a few demons get in and cripple the military. When a few flying demons sneak in through a hole someone made in the side of the base (you know, for garbage disposal), the entire military was decimated and we lost the hellbase.

Hmm... I guess it would be worthwhile to point out that this is Spearbreakers... We don't have the time to pass the linking of the traps to the next player.

It doesn't take a statue garden outside the gate to let invaders in, and it doesn't take building in front of fortifications to make them useless. If we ever get a real necro siege and they get into an area with spawn parts, we either turtle or we're screwed. And now there's
THIS new terror to deal with... I have no idea what a spawn lady is, but I would really,
really like to know
what it is, and how to defeat it to try to (hopefully) allow Sus to save the fortress. lol
Also, I may read Deathgate now. But that's offtopic.
And finally...
... urgent-Defcon1-calamity situations ...
Or, as the dwarves of Spearbreakers call it, Thursday.
This is gold,
So, uh... how screwed are we? Relative to our usual level of screwed-ness, I mean.
Tell me what a spawn Lady is and and I'll tell you how screwed we are.
this is gold,
By the way, WHAT IN ALL THE SIX-HUNDRED-AND-SIXTY-SIX MILE STRETCH OF THE PHLEGETHON IS A LADY OF THE SPAWN?!
It's obviously Spawny, now queen and come to negotiate a peace treaty. Let her in, oh wise one
I, uh... Already did. Thankfully spring came before she killed everyone, thus making it officially Sus' problem.
I knew I shouldn't have posted that comment about Draig having things "under control"... D:
Do we, uh, have any semblance of a useful military at all?
and this is adamantine. This last especially when coupled with:
I think he actually may not have gotten around to linking up all of the spikes, which would mean that our fortress is currently being defended by a bunch of really pointy lawn ornaments.
AND AN EDIT TO TOP IT ALL OFF:
Draignean, I looked through the raws, and I can't find "Lady of the Spawn" anywhere... My best guess is that it's simply a human-style lady/lord-ranked spawn... which could prove deadly, yeah. If they act like goblins, killing her may make the other spawn hang around for a bit... Yeah, we're screwed. Sus is going to have a Fun turn.

I hope this doesn't kill the fort. We may have to simply wall off the infected dwarves and hope for the best, if it's as bad as it sounds... I'm going to guess an 8 on the "Holy carp, we're screwed" scale... My suggestion would be to throw
EVERYONE at the spawn, all at once. They can't bite more than one person at a time, and dwarves will have the (hopeful) advantage of numbers. I just wish we'd had a chance to equip everyone with hammers first... When you're ready, upload the save and post or PM me a link, and I'll get it up.