In addition to the free character pack and the DLC mission that are available starting today, new weapons and cosmetics are joining the catalog too: Check out the trailer above for what’s in store. You’ll solve occult mysteries in Hell itself – lava pits bubbling in the backdrop, the sky painted a foreboding blood orange and legions of zombies (and manikins?!) following your every move. The four survivors are coming alongside the third and final chapter of Zombie Army 4’s Return to Hell campaign. Zombie Army 4 employs a third-person perspective, so while it might not feel exactly like the escapades that you and your buddies went on in Left 4 Dead 2, at least you’ll get a chance to finally see the character models in all their post-apocalyptic glory. Bill sacrifices himself to the hordes of infected to restart the generator, allowing Zoey, Louis, and Francis to go on without him.Coach, Ellis, Nick, and Rochelle are back again, almost as if they'd never left in the first place. Once all three are going, the survivors get on the bridge and raise it, but one of the generators gives out at the last moment. The sailboat is on the wrong side of a bridge that must be raised to let it through, and to raise the bridge, three noisy generators must be started. Here, they look for a sailboat so that they can fashion their own escape without the need to keep refueling. In the final campaign of this game, the survivors have taken a train to the port town of Rayford, Georgia. In a story told in the online comic "The Sacrifice", the survivors must eventually escape from the military base while leaving behind (for dead) a few of the people who helped them there. In the farmhouse, they use a radio to call the nearby military base, which after a few minutes of the survivors fighting more hordes, sends an APC to rescue the survivors and carry them to safety. They follow some train tracks to a train yard, and up a hill to the farm. The survivors find themselves in Allegheny National Forest, and see a Civil Emergency Defense Agency sign saying a safe zone has been established at the Daughtery Farm, with an address.
The C-130 crashes, though, possibly because of the pilot becoming infected as well. The fuel pump makes noise that attracts the infected, but when the plane is ready, the survivors hop in the back and it takes off. At the airport, the pilot of the plane they saw earlier asks them for help in fueling his plane up again. They decide to head for the airport to seek rescue. The survivors seek temporary shelter in a greenhouse, when they see an airplane fly overhead. Unfortunately, the Slaters take the survivors' guns and abandon them in the nearby city of Newburg, which is burning up in some areas. They make their way through Riverside to a boathouse, where they use a radio to call John and Amanda Slater to rescue them in their fishing boat. After he succumbs to the infection, the door unlocks and the survivors kill him. The "church guy" rings the bell and calls a horde. They enter Riverside through a church where a crazy man won't let them in his safe room. A destroyed bridge at a turnpike on the way to Riverside forces the survivors to fight through infected zombies again. They crash in nearby Whitney County, and from there cross a bridge on foot to a truck depot, where they take a truck and drive towards Riverside. Unfortunately, the pilot becomes infected and Zoey must shoot him. They make their way to Mercy Hospital, where the infection is suspected to have started, and are rescued by a news helicopter.
Bill, Louis, Francis, and Zoey find themselves stuck in the city of Fairfield, Pennsylvania in the middle of an epidemic known as the Green Flu.