The next chapter in Valve’s Left 4 Dead series, “The Sacrifice,” will be available on October 5. The DLC will cost Xbox 360 owners 560 MS Points ($7) while PC owners will get the content as a free update.

“The Sacrifice” is a prequel chapter and will advance the story previous told in “The Passing” DLC.

The next part becomes a little confusing, so try to follow along:

“The Sacrifice” will be available as separate downloads for Left 4 Dead and Left 4 Dead 2 discs. If you chose to download the DLC for the first games, thecontent will get you the complete “Sacrifice” campaign maps, playable in cooperative, versus, or survival.”

The Left 4 Dead 2 content will get you “The Sacrifice” campaign with the original Left 4 Dead survivors. Additionally, if you have purchased (or downloaded) Left 4 Dead‘s “No Mercy” campaign, it will be playable in Left 4 Dead as well.