In the middle of a tantrum spiral, expanding the catacombs, and not managing to keep ahead of the demand for burial space.
I started a new fort. In the second autumn a forgotten beast appeared in the caverns and proceeded to eradicate a tribe of batmen. Oddly, it kept on exuding a deadly gas and then getting caught in its own vapours. Lucky I sealed the caverns off completely for now.
Then the dwarven caravan arrived. And a goblin thief made it right to the depot in the heart of my fledgling fortress, scaring the merchants, who ran away, straight into an ambush of goblin lashers. I activated my tiny military of two hunter/marksdwarves and three miner militia who drove off the invaders but not before I'd lost half a dozen civilians in a fort of 40.
During the digging of burial chambers, construction of coffins and memorial slabs, and hauling of corpses, one of my miners went berserk, and killed another miner and marksdwarf before being put down. Dwarves were tantrumming and overturning coffins before the corpses could be interred. There were some fist fights and then a murder. So I assigned a sheriff who went around beating up criminals, when he wasn't tantrumming himself. He killed a couple of criminals too. The outpost liaison left unhappy when my expedition leader turned melancholy. The replacement expedition leader got himself imprisoned, went berserk himself while still chained, causing job cancellation spam from every dwarf that walked past him until he was put down.
Too much FUN. Also, stone traps are worse than useless.