The second Left 4 Dead television commercial starts its run on network and cable television tomorrow — Tuesday, November 18 — the same day Valve's zombie thriller launches worldwide on Steam. The commercial is part of a $10 million marketing campaign for the highly-anticipated title, which is available for a special pre-order price until the time of launch at participating retail outlets and via Steam.

The second TV spot is available in 720p and 1080p formats as well as downloadable versions for your iPod and iPhone.