Valve has released the 5 minute opening sequence to their 4 player co-op zombie shooter, Left 4 Dead. The intro follows our four protagonists as they investigate crying in a building, and then...well...zombies can cry. And you might too.
The rest of the video is filled with lots of running, screaming, shooting, and exploding heads. Sounds like a good Saturday night to me..
Source: Gametrailers.com