Valve has announced a new three-map campaign for cooperative zombie shooters Left 4 Dead and Left 4 Dead 2.
Left 4 Dead writer Chet Faliszek popped up on GameTrailers to make the announcement.
The Sacrifice, due out on 5th October for 560 Microsoft Points (£4.80 / €6.72), lets you play as the characters from the first game in a setting designed to provide insight into how the survivors from each game met during previous downloadable campaign The Passing.
It allows players to decide which member will permanently die at the end of the chapter, instead of the forced choice seen in The Passing.
All players will get a four-part digital comic designed to tell a canonical version of which character is supposed to die.
While you play as the Left 4 Dead 1 characters in Left 4 Dead maps, weapons introduced in Left 4 Dead 2, including melee weapons, the M60 machine guns and the defib, will be available.
Additionally, Valve will bring the No Mercy campaign from the first game to the sequel.
As is the norm, Xbox 360 owners will pay for the DLC, while PC and Mac users get it free.
Left 4 Dead 2 was released in November 2009. Eurogamer gave it a 9/10 review.