We just had a forgotten beast get in. A lone bowdwarf killed it with a sword on the first hit. Not a bad fight.
It's been nearly two months since I gave the orders for the levers to be pulled. One out of three have actually been pulled. The next one will either set the outside on fire, or flood the fortress. Our main dining room is a cloud of miasma. The caverns have mysteriously flooded, and threaten to flood the lower fortress (this isn't a good thing: the magma levers are down there). A peasant has been stuck on "Attend meeting" for no apparent reason all year. I keep finding more an more tunnels under the walls from the last turn. No wonder we died out: This place is about as insecure as it's possible to be.
I'll give it another month. After that I'll cancel all labors and order them to dismantle the housing for the Shroud of Armok. It won't be as effective as the full purge function....but it should work well enough.
Edit: Also, they're still pushing the corpse-minecart. Apparently it actually killed off poor Meng.
Edit2: More madness. Second lever pulled. Exterior of fortress now on fire. Moving a squad up to the towers so they can watch.
Edit3: Dwarf (Sebastian2203) decides to go looking outside for new clothes on bodies. Decides carrying giant rock while doing so is excellent idea. Notices giant forest fire. Thinks "There must be socks in there!" and goes for it. Realises mistake, drops rock and dodges the flames. Runs ~5-10 metres then decides to have a nap. Gentlepersons, I think we have our Most Stupid Death of the Succession.
Edit4: Apparently all our dwarves are pathing through the caverns because someone opened up multiple routes through them without having a way to shut them off. I'm going to have to break the Shroud, I think.
Edit5: On the other hand, a child grew up, so that's one more chance to pull the damned lever. Come on, guys! Pull it!
Edit6: I'll update again later today. I think I broke the Shroud.
Edit7: I did...in the least lethal way possible. Update postponed for a bit because of coursework. It'll be a few days. Fire has gone out because of rain.