Dead Air

Dead Air is the third campaign in Left 4 Dead, spanning five chapters. The Survivors must make their way through Newburg to a runway in hope of catching a plane from Metro International Airport to get away from the Infected. To get there, they must start their trek from a greenhouse, head past a crane, move through a construction site, traverse the airport terminal, and finally reach a runway where a military C-130 Hercules aeroplane is waiting to evacuate them.

Below are walkthrough videos for each of the 5 chapters:


 * 1) The Greenhouse
 * 2) The Crane
 * 3) The Construction Site
 * 4) The Terminal
 * 5) Runway Finale

Official description
Guide your team of Survivors out of the downtown core of Newburg's business district, through derelict office floors and still-inhabited cubicles, and out onto the runway of Metro International Airport, where the only thing standing between you and the last plane out of the city is a murderous army of the undead.

Graffiti

 * There are several instances on the rooftops where one may find writing, such as "Help! Need food." or "S.O.S." There are also numerous writings about how a bomb will be dropped on the airport.
 * In The Terminal's starting safe room, a piece of graffiti states; "WE ARE THE REAL MONSTERS" on the wall, along with various other messages below it telling the writer that they are a moron, telling them that the Infected are the real monsters, and somebody even tells them that he wishes that they are dead now.
 * On the same wall, written in small letters, is the infamous graffiti, stating; "I miss the internet".
 * In one sentence, it claims that the Infected were created by the military. Following that, there is a rumor that the government is giving a cure to the rich. Below that is a claim that the virus was made by aliens, along with a writing saying "What if this was first contact?" followed by "What if your a moron?".
 * Several times throughout the campaign, the phrase "God is dead" can be seen. This was a statement originally made by the German philosopher Friedrich Nietzsche, and has heavily been quoted since. Occasionally, the Survivors may respond to the writings, saying things such as, "Oh, no! The zombies killed God!"
 * In the safe room of The Crane, there is some graffiti on the wall that states "This is our punishment." Right under this is the sentence "It's just Dead Air." - a reference to the title of the campaign.

Trivia

 * Out of all four main campaigns, this one has the most unexplainable starting location for the Survivors.
 * During the level The Terminal, there is a large statue of the Greek titan Atlas. When Zoey comes across this statue, she will sometimes say, "Look, it's Ayn Rand International Airport." This is a reference to Ayn Rand's novel, Atlas Shrugged. Francis may sometimes reply with; "I hate Ayn Rand."
 * The graffiti throughout the campaign claims that the airport has been bombed. Their predictions look to have come true when the Survivors enter the ruined facility. This is also mentioned in random dialogue by Survivors. Near the end of Runway Finale, sometimes the Survivors may state the airport was bombed to prevent the Infection from spreading. Also, near the skyway in The Terminal, Francis may say, "What idiot bombed the airport?"
 * However, it has been noted that the debris of a plane can be seen scattered through out the airport, leading to an alternate scenario: A plane crashed mid flight, and the bomb has yet to be dropped.