Strategy Informer  

Payday: The Heist developer Overkill Entertainment announced a partnership with Valve last month, although what the two firms would be working on wasn't clear until now.

According to a source close to CVG, Overkill are working on a Left 4 Dead game that will tell the story of a zombie outbreak before the original Left 4 Dead.

Overkill described the game as a "very cool blend of Payday and Left 4 Dead".

"As perceptive gamers will have noticed, several hints have recently been dropped into Payday: The Heist, which has led to various rumors," read the statement from Overkill. "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. I am sure it is so exciting that it will have some players check into the hospital before we are done."

It's been over two years since the release of Left 4 Dead 2, so you'd think we're about due for a third addition.

Related games: Left 4 Dead 2 (PC), Left 4 Dead (Xbox360), Left 4 Dead 2 (Xbox360), Left 4 Dead (PC)