A vile force of darkness arrived; this was pretty confusing for me, as the last squad they sent all died in the large-scale drowning trap coloquially referred to as "Gravegranite's only entrance" and I absolutely cannot understand how throwing more troops into it is supposed to fix that.
Unfortunately, there was a slight technical difficulty on my end (by which I mean "I forgot which lever started the doompumps") and, while I was ordering what I thought was the watery-death-lever to be pulled and wondering why nothing was happening (which, incidentally, was because the lever, in fact, did not operate the doompumps but rather a set of submerged* spike traps**), the goblins managed to make it to the end of my entrance and let themselves in to my fortress, after which they immediately began to chase after my defenseless civilians while I prepared for a massacre-induced tantrum spiral and ordered my military to get off their copper-plated asses.
After the carnage had ended, I was left with a grand total of 0 killed, 0 injured, 21 iron bars worth of meltable goblinite equipment, 300 zillion rotting gobbo parts to clean up, and a suspicion that my fortress is occupied by some kind of catastrophe-preventing voodoo spirit.
* No, they aren't supposed to be submerged. Fortunately, they are located in a part of my fortress that no being has any earthly reason to enter, so it doesn't really affect their performance either way.
** I *think* that's what that lever did. I honestly don't know and have no way of testing which doesn't risk flooding my whole fortress.