Dwarf Fortress has become such a complicated society simulator that almost any new bit of information is automatically interesting—it's a game in which you can use vampires to power logic computers, for example. In an update on the Steam version, co-creator Tarn Adams explains a bit about how enemy agents will try to infiltrate your fortresses and recruit your dwarfs for their malevolent goals.
One of the new dynamics coming to Dwarf Fortress, along with its Steam launch, is the presence of villainous networks in the game world. Each time Dwarf Fortress creates a new world, it fills that world with years and years of history, and that history dictates which groups wind up in which areas of the map (among many, many other things). Now, part of that history will establish nefarious groups, which can grow and spread to multiple sites. This all happens before you even start playing the game, it's worth pointing out.
As your fortress grows bigger and wealthier, it'll eventually attract the attention of one or more of these groups. Adams explains that unlike your normal invaders—goblin hordes, elephant stampedes, you know, the usual—villains will send agents into your fortress, disguised as some other kind of visiting dignitary, merchant, or scholar.
But these agents can't just put on a disguise and waltz in. They need some kind of cover story, and Adams and Co. have devised a way for the game to provide exactly that.
"They do this by scanning the sites near your fortress for matching population types, and pick professions that those sites use," Adams writes in the latest update on Steam. "So a villain might send a corrupt human justicar to your fortress under cover as a visiting astronomer, if you have a library and there is a human civilization that values scholarship nearby."
Very devious indeed! Once they've entered your fortress, these spies will seek out dwarfs they can corrupt using flattery, bribes, or promises of revenge. And it'll be up to you and your dwarfs to conduct investigations into what's afoot once you've cottoned on to the fact that someone is sowing discord in your community.
Adams says he'll share more about what corrupted dwarfs will get up to in a future update. There's no launch date yet for the Steam launch of Dwarf Fortress, and right now the page still says "time is subjective" in the space where the planned release date is meant to go.