Sweden's Overkill Software, the crew behind last year's respected co-operative shooter PAYDAY: The Heist, let loose some precious insight into that illusive Valve's upcoming plans. It isn't details on Half-Life 3, but it is word that Overkill is collaborating with Valve on a brand new project. 'New' is always an exciting word to hear in conjunction with Valve.

Overkill director Ulf Andersson released this statement on the studio's website on Monday: "As perceptive gamers will have noticed, several hints have recently been dropped into PAYDAY: The Heist, which has led to various rumors. 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."

Now that's how you tease a game. It comes after other teases alluded to by Andersson in his statement. A patch released for PAYDAY earlier this month leaked goods into the game like a table full of Left 4 Dead’s iconic health packs. Whether this collaboration will just yield new content for PAYDAY or a whole new game is unknown.

PlayStation 3 owners should be especially encouraged by Andersson’s tease. PAYDAY is only available on PC and PlayStation 3 meaning that this collaboration will be the Left 4 Dead series debut on Sony’s machine in any capacity.