Lead Designer on Crackdown 2 Steve Iannetta has revealed in an interview with Joystiq that the back story to Crackdown 2 is based on a mission that happens in the first game.
The sequel takes place ten years after the original, where the Shi-Gen from the original game are now commonly known as The Freaks in CD2 after releasing the prisoners from the corp in the first game.
"Well "The Freaks" were from the first game. The Shi-Gen -- once you killed the boss -- you unleashed the freaks into the world. Basically it's a continuation of that," said Iannetta.
"It's ten years later and because of your actions you've turned the city into, basically, a living hell. Nighttime is just "freak" time. You can't go out at night. Daytime civilians are scurrying about trying to get themselves the necessities of life and when it comes to dusk you'll see them scuttling home."
Game's out in 2010 for the 360.