Blood Harvest

Blood Harvest is the fifth (originally, fourth) campaign in Left 4 Dead. The Survivors must travel to a barricaded farmhouse and get rescued by the United States military. The escape vehicle is a United States military armored personnel carrier. Although there is no official chronological order to the campaigns in Left 4 Dead, it is believed that Blood Harvest is the last since the Survivors are rescued by the military in the end, and not by an unofficial evacuation method. The Survivors are taken to Millhaven by the military at the end of this campaign and make their way south on a train as explained in the canonically correct comic The Sacrifice, along with the campaign of the same name.

Below is a complete list of video walkthroughs of the 5 levels:


 * 1) The Woods
 * 2) The Tunnel
 * 3) The Bridge
 * 4) The Train Station
 * 5) Farmhouse Finale

Please note that the gameplay videos are on each campaign's info page not on each map page.

Official description
Zombies lurk behind every tree, over every hilltop and behind every shadow in this terrifying moonlit search for a rumored evacuation zone to the north: several acres of back-country farmland taken over by the military to get the last of humanity out of Ground Zero. Plunge through pitch-black forests, stumble blindly through fields of swaying corn, and take aim at the silhouettes leaping at you from the darkness—all towards finding a hold-out that might already have been abandoned to the horde.

Graffiti
In the safe rooms, the writings on the wall are telling the remaining Survivors to follow the train tracks to get evacuated to the safe zone. Additionally, when walking to the farm where the APC will arrive, there will be two signs on a post. Both appear to be from the military. One says "Keep your hands above your head in the field at all times or you will be shot on sight!" while another says: These signs are to help the military tell who is infected and who is not.
 * 1) Do not run at military personnel.
 * 2) Do not ignore personnel when they address you.
 * 3) Do not make any violent or sudden movements.

Similar signs can also be seen when arriving at the Bridge in Left 4 Dead 2.

At the Farmhouse Finale the map on the wall just behind the radio that activates the finale, at the top right hand corner the map is labeled Candy Mountain.

Setting
As revealed by a park sign at the starting location, this campaign takes place in and around Allegheny National Forest in Western Pennsylvania, a couple hours' drive from the city of Pittsburgh. Pittsburgh (and its surrounding region) is famous for providing the settings to many films such as Night of the Living Dead and Dawn of the Dead. The comic The Sacrifice confirms this by having a note about Evacuation Outpost Echo (aka the farmhouse) being in upstate Pennsylvania.

Behind the Scenes
Beta versions of Blood Harvest were much greener and brighter than the final version. In addition, there is no fog, making the sky much more visible.

Achievements

 * See Main Article: Achievements