Swamp Fever

Swamp Fever is Left 4 Dead 2 ' s fourth campaign (originally the third, with The Passing DLC shifting campaign order).

Swamp Fever spans four long chapters and takes place in Louisiana-type bayous and swamplands near a shanty town called Village En Marais.

Chronologically, it follows on from Dark Carnival and picks up the Survivors' story in wake of Nick shooting the helicopter pilot due to the latter becoming an Infected. Once they have shaken themselves out following the helicopter crash, the Survivors find themselves stranded in the middle of nowhere with their only obvious route to safety taking them through a gator farm, swamps and hardscrabble settlements overrun with Infected. Along the way they encounter the remains of a recently crashed commercial jet, a new discovered breed of Infected in the form of Mud Men and the decayed grandeur of an antebellum Plantation House.

The campaign culminates in a finale wherein The Survivors must hold out until rescued by a fishing boat captained by Virgil―a likable and public-spirited Cajun.

Swamp Fever is the only campaign to contain Mud Men (a class of Uncommon Infected) who are agile, hard to spot and blur the player's vision with mud when attacking. Similar to Jockeys, they move by scuttling along on all fours, but they are of a bigger size and so are easier to hit.

Achievements

 * See Main Article: Achievements

Behind the Scenes
Originally the Uncommon Infected were the Fallen Survivors instead of the Mud Men, but they were cut from the game and later put in The Passing. Also, the Heavy Machine Gun at the finale was going to be in front of the entrance of the house, not on the 2nd floor balcony.