Valve have shot through a reminder shout out that "The Sacrifice" DLC (downloadable content) for Left 4 Dead and Left 4 Dead 2 will be arriving on Steam and the Xbox Live Marketplace this October 5 as two separate downloads for each version of the game (ie the first game and the sequel).
"The Sacrifice" is the prequel to "The Passing," and takes place from the L4D Survivors' perspective as they make their way South. In addition to advancing the story, "The Sacrifice" introduces a new style finale featuring "Sacrificial Gameplay" where players get to decide who will give their life so the others may live.
In The Sacrifice for Left 4 Dead 1 gamers receive the complete Sacrifice campaign with maps playable in Campaign, Versus, and Survival.
In The Sacrifice for Left 4 Dead 2 owners receive "The Sacrifice" campaign playable with the Left 4 Dead Survivors. In addition, those with Left 4 Dead 2 receive L4D's "No Mercy" campaign. Both campaigns are playable in Campaign, Versus, Survival, and Scavenge modes and both will feature the Left 4 Dead 2 Special Infected, items, and weapons. Yes, Zoey with a chainsaw!
As with most things Valve do, this one is very much a PC-friendly release; arriving for free, while Xbox Live users with be charged 560MS Points.