Valve announced today that the next downloadable update for Left 4 Dead, Crash Course, will be released for the Xbox 360 and PC on Tuesday, September 29th. It will be free on the PC and 560 Microsoft Points ($7) for the 360.

Crash Course adds a new cooperative campaign that is said to connect the storylines of the "No Mercy" and "Death Toll" campaigns. It'll probably be a bit shorter than a normal campaign though, as the stated goal of the DLC is to "deliver a complete Versus mode experience in just 30 minutes." The DLC pack also includes new maps for Survival mode.

This is the first new campaign to be added to the game since its release last November. The previous DLC, the Survival Pack, introduced Survival mode and added Survival mode support to two retail campaigns that lacked it.