Via the official website Valve has revealed that the first expansion of Left 4 Dead 2 called The Passing added, plus a new set of missions in single, multiplayer and co-op, including novel ways to game that, as that are looming very interesting. The publisher will disseminate details about the coming days. While waiting to find out more, we remind you that the pack is expected on the Marketplace in April, the exact day has not been made official.