About two years into my current Steam release DF fort. Things were going pretty well for the first year — the tutorial actually chose a decent site, easy water access, lots of trees, mild winters, a big waterfall ravine for me to build in and get free mist bonuses.
The around Spring of year 2 I had a... well I'm not actually sure what kind of invasion it is. Two humans, two goblins, two zombie dwarves. I was somewhat prepared for this, so I immediately pulled up the drawbridge, leaving anyone outside the fort to die. Then my woodcutter did a sick parkour trick past the defences. So I had to wall off the entrance (and all of the nice waterfall stuff) to ensure the safety of the fort.
I'm mostly self-sustaining, but I wasn't really prepared to have to build the soap industry from scratch, nor the cloth industry I need to have enough bags to make soap. So someone is slowly dying of infection after a fight with a giant bat underground. A lot of humans have been visiting, then dying to the invaders. One even managed to kill one of the zombie dwarves. I hope they leave soon.