Are you absolutely, er, perishing to play Left 4 Dead? Well, Valve has your back. Simply plunk down $5 on the undead murder simulator and you'll unlock a free demo on November 6 -- five days before everyone else.

"This pre-order promotion applies to all Steam PC pre-orders and all Xbox 360 and PC pre-orders from participating retailers in North America," read the press release. GameStop is the only confirmed retailer at the moment.

The demo will serve up both single player and co-op modes for 1-4 players. Since the demo's spewing a bubbling concoction of content, there is, of course, a catch: the demo -- like an zombie Undead American with a live grenade jammed down its throat -- will only be active for a finite amount of time.

"The demo concludes on November 18, when Left 4 Dead will be made available at retail outlets across North America and worldwide via Steam," notes the press release.

All told, though, we're pretty excited about this. Oh sure, we could give Valve a stern talking to for falling into the retail trap of giving preferential treatment to pre-orderers, but it's Left 4 Dead, guys. No matter how sordid the method of delivery, if we snag some hands-on time, we'll be too disgustingly over-joyed to care.