After the Soviets unleashed zombies upon Soviet Russia to stop the advancing Americans, the Americans, British, and Germans created a league known as the International Creature Elimination Force (also known as I.C.E.F.). Thousand of soldiers from each country were sent to an area to handle the zombies The Americans and Germans were sent to South America, the British were sent to Iraq, Afghanistan, and Uzbekistan. The Chinese refused help and remained secretive in some odd plan. The three nations in the I.C.E.F. held out as long as they could, but eventually had to retreat due to the overwhelming amount of zombies. During a meeting between the leaders of the I.C.E.F., they discussed more possibilities to defeat the zombies, even though the zombie apocalypse was inevitable (and they knew it). Weeks passed, and unfortunately the zombie apocalypse had occured. America, Soviet Russia, China, half of South America, all of the Middle East, and a few countries in Europe had succumbed to the zombies. The world couldn't but wonder why the amount of zombies seemed to regenerate every week. Shortly, the I.C.E.F. had constructed a permanent base in Antarctica, which served as a base of operations. Many plans were discussed, and finally, they came to the conclusion that Russia had to be nuked. This would, in their thoughts, end the regeneration of zombies, and they could focus on the surviving zombies in South America, America, Europe, China, Iraq, Afghanistan, Uzbekistan, and now the northern tip of Africa.
After the nuclear missiles were launched, the I.C.E.F. invaded Europe. When they arrived, the I.C.E.F. soldiers stormed any area thought to contain zombies. During the battle, Maestas, Bryan Aziz, Micah Shabs, and Drew Winters had become seperated from their unit and were forced to fight hundreds of zombies.
During roll call, the I.C.E.F. learned that Shabs, Winters Aziz, and Maestas had become seperated and left behind. They sent a rescue force to retrieve them. The rescue mission was a success.
After the war ended in 1973, America was rebuilt. Using advanced techology, more utilities were added the cities. America had become a thriving metropolis once again. However, zombies still remained. Maestas, Aziz, Shabs, and Winters were sent in to clear out zombies from New Columbus.
The four succeeded, and were retrieved by Huey and flown back to a military base. Each soldier was awarded the Silver Star for their actions. Unfortunately, the I.C.E.F. was disbanded shortly after, and the four were returned to Central Intelligence Agency as special agents.
The four Central Intelligence Agency special agents were able to explore the USS Constellation while fighting zombies. Upon entering the control room, one of the agents notices a paper laying on the control desks. He picks it up, and rejoins the other agents. They race back out to the deck, and are retrieved by a Huey. The Huey flies them back to the United States, to the Hexagon. The agent who collected the document shows it to generals of the Special Activities Division. The generals study them, and find coordinates to a base in South America. The CIA's best agents—Micah Shabs, Drew Winters, Bryan Aziz, and Nicholaus Maestas—are sent to the coordinates to investigate.
The four are flown via Huey to compound. The four exit the helicopter and begin walking towards the facility. Maestas kicked the door down, and all four breach. When they entered the control room they are instantly attacked by zombies.
While fighting zombies in the Amazon Rainforest, Maestas, Winters, Shabs, and Aziz came across a door that had not been opened. Drew Winters kicked the door down, and the four agents entered. The four immediately noticed a staircase that led down into a room. When the four reached the bottom of the staircase, zombie started to attack them. Winters, Shabs, Maestas, and Aziz once again are forced to fight the undead horde.
Later, the four are retrieved and taken back to New America.