We'd previously heard that Payday: The Heist developers Overkill are working on a game with Valve , but details were scant - all we knew is that it was Left 4 Dead related. Our megapals over at CVG cite a source as saying that it's going to be a Left 4 Dead prequel which details the genesis of the zombie uprising.
"As perceptive gamers will have noticed, several hints have recently been dropped into Payday: The Heist, which has led to various rumors," the original statement from Overkill read. "We are excited to be able to confirm that an in-depth collaboration between Overkill and Valve is currently in production. We are working on a very cool blend of Payday and Left 4 Dead."
It's a really nice idea for a collaboration. In Left 4 Dead you're the good guys. In Payday, you're the bad guys. Combining of the two, you could be a bunch of morally grey guys. Also, it's a prequel, and everyone loves prequels, right? If not, don't worry: Overkill are also working on a sequel to Payday: The Heist .