Description: (Downloadable Content) Left 4 Dead's latest DLC delivers an all-new single-player, multiplayer and co-operative gameplay experience, expanding the game universe with new locations, new dialogue from the original cast, and an explosive finale. At the finale of No Mercy, our four Survivors fought their way to the rooftop of Mercy Hospital, where they were flown away to safety in a helicopter. Crash Course continues the story moments later, taking our heroes from a fiery helicopter crash in the outskirts of Riverside to the escape vehicle that will lead them to the events in Death Toll. While containing both Survival maps and a Co-operative Campaign, one of the primary goal of Crash Course is Versus mode. Crash delivers a complete, streamlined Versus mode experience in just 30 minutes. A recharge timer for infected teammates has also been added, so you can better coordinate your attacks. Item spawn behavior has changed for more balanced gameplay. [Valve]