Last month, PAYDAY: The Heist developer, OVERKILL Software, announced that they would be working with Valve on a project. A trailer for the project has been posted today, and should be of great interest to fans of both franchises.
PAYDAY: No Mercy is a new campaign for the game taking place in Mercy Hospital, the same hospital where you start off in Left 4 Dead. In the trailer, your crew has to get blood from someone that is quarantined within the hospital which could mean that this is the act that started the outbreak of the Left 4 Dead games. No date or price has been given for the release of this campaign.