Valve has revealed the first expansion to Left 4 Dead 2, The Passing. The campaign, set after the events of Dead Center, includes an encounter where Ellis, Coach, Rochelle, and Nick meet up with Bill, Francis, Zoey and Louis. This is more than just a friendly survivor get-together, however, as Valve has added a new infected type, new weapons and another coop challenge. The expansion is set to release this spring for both the PC and the Xbox 360.

Source: Kotaku