Redemption takes place midway through the L4D comic strip, it continues the story after the survivors flee the military base they were taken to after blood harvest and that leads to the Sacrifice campaign.

The campaign includes:
* 5 large maps that traverse through a new and revealing HELIX Research environment
* 5 Completley New Melee weapons (They DONT replace any other Melee!!)
* Custom content including textures, models, sounds, particles and ingame animation
* Extensive detail overhaul from the L4D version
* NPC's that add to the unfolding storyline
* New panic events & traps
* Dynamic supplies and paths
* Easter eggs & New final mechanic