Summer, 2nd year
Rhymes with "ducked".
So I got a huge immigrant wave - and by huge, I mean that the 18 spare bedrooms I had weren't even close to sufficient for the massive influx - 50 odd dwarves, half of which were children. I got bed-building and room digging tasks up there pronto but summer showed up and a vast undead invasion siege of 80 creatures or so turned up at the beginning of summer.
Just one of these creatures could wipe out my fort, let alone 80.
I'm cheating a bit, admittedly - it's a harder embark than I normally try. I tried leaving it as it is - sealing the base, then hoping the invaders would sod off. But if just one climbs the exterior wall (and twice, they did, thank heavens for the 'die' command in dfhack), a single zombie will happily slaughter my entire fort with or without copper weapons. So not good, not good at all.
Instead, I've decided to wall off all stairwells. This is a terrible strategy - there's now no access to farms or livestock, and probably not effective - where I've had to build the walls they're still climbable (though less accessible).
So what the hell do I do now? My food/booze supplies are not great (200ish of each) giving my fortress about 6 months to live unless I can somehow establish lower level farms (hurting this is no real access to water and the fact that almost all my seeds are currently planted in now inaccessible areas). I have rapidly dimishing supplies of wood and no coal.
My suggested solution at this stage is to try to wall off "properly", and try to breach the caverns like right now. Without any sort of military presence or constructing proper sealable bridges this is a choice between dying by zombies and dying by the first forgotten beast that shows its face. Also: Even if the undead siege sods off I basically will have few seeds to re-establish the farms, and I'm kind of assuming the livestock will get zombified and *won't* sod off - giving me a second, difficult to solve problem.
I love this game