Valve has announced a new downloadable content pack for both Left 4 Dead and Left 4 Dead 2, called “The Sacrifice.”

In it, players will take control of Left 4 Dead’s Francis, Louis, Zoe and Bill in the events leading up to their recent cameo in Left 4 Dead 2 DLC, “The Passing.”

In The Passing, one of the original survivors had been written out of the game. In “The Sacrifice” players will be able to choose which of the original foursome dies.

Additionally, Valve will be bringing Left 4 Dead campaign “No Mercy” over to Left 4 Dead 2.

Finally, the developer will also be digitally publishing a 150 page comic, providing extensive background information on Left 4 Dead’s story.

As always, PC and Mac owners will get the DLC for free. Xbox 360 players will need to appease Microsoft with a handful of change.