Channeledice went dead, or rather, undead. I decided I'd build a 37-pump stack to carry water from my first cavern to my fort proper, which is where I was establishing a hospital in prep for beginning military training. I spent so much time concentrating on it that I failed to notice a caged stray donkey had somehow gotten into my primary stockpile depot. It died, came back to life (outside its cage!), and proceeded to charge down into my main shaft into the heart of my fortress. After half a dozen deaths, absolute panic, the collapse of my incomplete pump stack, and general shenanigans, I ended up calling it, especially with a new version to play with.
Lessons learned:
1. Compartmentalization and decentralization. To date, all of my forts have been focused around a single shaft, which might at the most shift slightly based on geographic features like aquifers or caverns (weird past fort: sinking the main shaft right on the boundary between two biomes, which I wouldn't have noticed if they hadn't had two different aquifer depths). There is no way to seal the main shaft once an enemy gets inside of it, nor is there any alternate means of vertical movement. Next fort, I think I'll sink satellite shafts and living areas, and set up some way to compartmentalize my entire fort if need be. Or at least set up traps in all the corridors.
2. Pump stacks. Never wire up an incomplete pump stack and turn on the power, even if the actual connecting gears to the stack in question are shut off by a lever. I did this, connecting it to my dwarven Heavy Pressurized Water Reactor (not to be confused with a Pressurized Heavy Water Reactor), and the game processed the pump stack (even though it was unpowered - I saw the static axles), realized there was nothing holding up any of the completed individual pumps save for wishes and dreams, and promptly deconstructed the entire thing.
3. Undead don't die in magma if they're in a cage. They just burn, stinking up my fort. *sigh* The cage wasn't even magma-safe (copper). At least I found that out before creating a magma flood trap.
4. Undead parts, even stripped to bones, will still revive. Yeti right hand bone, locked in my refuse dump,goes on a rampage of one, stopped only by the humble cage traps I set up outside the double-doors. <_<
5. Strange mood dwarves are even more suicidal than normal dwarves, if that's possible. I lost my second-best mason that way, and had to lock both the mason and zombie (and mason zombie) in one of my masonry workshops. I guess the possessing spirit just really wanted company.
6. When you set up a double-hatch airlock entrance, always keep at least one door closed. I literally had a zombie right outside the bridge that served as an inner hatch by the time I managed to get it shut. On that note, zombies that get flipped by bridges are not stunned, making atom-crushing on the fly a little trickier.
7. Liaisons can really *run* when they're chased by angry undead yetis. Just goes to show how motivation is key.