Like Left 4 Dead, the sequel involves the aftermath of an
apocalyptic pandemic. There has been an outbreak of a
rabies-like pathogen that causes infected humans to behave
like zombies. The four survivors have to fight their way
through the hordes of infected, using safehouses along the
way to rest and recover, in order to reach extraction points.
Left 4 Dead 2 is set in the Southern United States, starting
in Savannah, Georgia and ending in New Orleans, Louisiana.
Left 4 Dead 2 introduces four new survivors, whose backstory
will again be provided through dialogue. Unlike the first
game where there was no significant story development,
Left 4 Dead 2 will feature a story arc.
Several new features are introduced, such as new types of
infected, melee weapons, and a story-arc that connects
each of the game's five campaigns together.