Valve has announced that their upcoming sequel to Left 4 Dead, Left 4 Dead 2 (L4D2), will be playable at the upcoming Penny Arcade Expo September 4-6.

After debuting "The Parish" campaign (set in the New Orleans' French Quarter) at E3, and "Swamp Fever" at Comic Con San Diego, the PAX showing will unveil "Dark Carnival", the third of the five campaigns shipping with L4D2 this fall. The game will be playable in Microsoft's Xbox 360 booth as well as in Valve's L4D2 booth. Different areas of the game will be shown in each location.

In addition to the new campaign, Valve is also planning to unveil a few more of the 20-plus new items coming this November when the title launches on the Xbox 360 and PC. For more information, please visit www.l4d.com