Forced Evolutionary Virus



The Forced Evolutionary Virus (FEV) is, aside from environmental radiation, the major source of mutation in the Fallout universe. Most importantly, both Super Mutants and the Master are the result of infection by FEV. Aside from Super Mutants, the Master also created a variety of other aberrational creatures using the virus. The FEV existed in various forms in all the Fallout games. Its various forms created two major threats to post-nuclear humanity: the Super Mutants of the Master, and their Capital Wasteland counterparts, created in Vault 87. The FEV virus gave birth to a wide variety of dangerous creatures (including the Master and Frank Horrigan) which not only became a threat to post-nuclear humanity, but also served as the means by which the games' antagonists sought to achieve their goals.

Before the Great War
In the years immediately preceding the Great War of 2077 between China and the United States, both sides were scrambling to research a new weapon that would give them an edge in the coming conflict. What the Chinese research teams developed is unknown, but the United States government tapped the resources of American private industry to develop a secret weapon that could defeat the Chinese. One company, a high-technology scientific research firm named West Tek, was already a major American defense contractor. In the first Fallout, the Vault Dweller explored a location in the Core Region Wasteland called the Glow, which was in fact an underground West Tek Research Facility that had been directly targeted by Chinese nuclear warheads during the Great War. While exploring the highly radioactive ruins, the Vault Dweller discovered that West Tek had created a number of useful things for the American military. Potent laser and plasma weapons were being experimented with there. Power Armor, the massive self-contained suits of mechanized combat armor that turned a single soldier into a walking tank, were also developed there. And most importantly, important research into immunity-boosting drugs designed to combat biological weapons agents was being conducted by West Tek.

One fear among the brass of the American military of this period was that the Chinese would deploy biological weapons against American troops: these would be powerful, genetically-engineered super viruses that would decimate other armies and civilian populations without a single shot being fired. Thus, West Tek had initiated the Pan-Immunity Virion Project (PVP) to develop a way to stimulate the human immunological system in such a way that the human body's natural immune system could be used to counteract any Chinese biological agents. It was determined that the way to achieve this was to alter the subject's DNA in such a way that the changes would cause disease immunity by transforming human DNA's dual helical structure into a quadruple helical structure. Such an alteration would make it impossible for almost any known or engineered pathogen to infect human cells modified in this way. During West Tek's testing phase of the PVP in 2076, abnormal side effects were observed developing in the test subjects. The test animals began to grow dramatically larger in size and muscular structure and their brain activity increased. Seeing the potential military applications of these unexpected results, the U.S. Army sent its own military scientists into the facility to secure the project and renamed the PVP virus the Forced Evolutionary Virus (FEV). Not content with producing mere immunity to disease, the Army's researchers hoped that the FEV would turn its soldiers into abnormally strong and intelligent supermen capable of defeating many times their own number of Chinese soldiers. When the testing on animals reached its logical conclusion, the American military moved the entire apparatus of FEV research to its own Mariposa Military Base in California where secret human testing on military prison inmates proceeded.

The Great War
However, the grim nature of the research being carried out at Mariposa greatly unnerved the members of the U.S. Army garrison guarding the base. The nature of the military scientists' work, which had until then been kept a secret from the Army grunts, caused them to revolt when they discovered the truth. Colonel Robert Spindel, the officer in charge of the garrison, lost his mind and committed suicide. His second in command, Captain Roger Maxson, took command of the troops and began interrogating the Mariposa scientists. Rattled by the vile things the scientists were doing to their test subjects and incredulous of the claim that the science team was only following orders that had been handed down from the highest levels of the Pentagon, Captain Maxson had the researchers executed one after the other. Later, he announced the Mariposa Military Base to be in full secession from the United States and his own unit to have left the U.S. Army. Only days after these actions in October 2077, the Sino-American War reached its ultimate climax as Chinese nuclear bombs and warheads fell from the sky and the United States ceased to exist as a unified nation. Disgusted with the Mariposa base, haunted by the fate of the FEV test subjects and the executed scientists, Maxson decided to lead his troops and their families to the federal government's Lost Hills emergency bunker, where they would later use their high technology military equipment and knowledge brought from the Mariposa Base to form the Brotherhood of Steel.

Richard Grey's Expedition
The Mariposa Military Base was quiet for a long time after the bombs fell. Not long after the Great War, however, a group of explorers from the Core Region Wasteland, including the future mutant Harold, entered the base looking to end a peculiar proliferation of mutated animals which seemed to be coming from the installation. The exact date of the expedition is unknown, but Harold's presence while still a human being suggests that it could not have been more than ten to thirty years after the bombs fell; since Harold is known to have been a Vault dweller who emerged shortly after the Great War's end. Thus, to still be alive and human, Harold have had to have entered the base not long after the war.

Leading the expedition was Dr. Richard Grey, previously known as Richard Moreau until he was exiled from Vault City, a nearby settlement in the Wasteland. When Grey's team entered the Mariposa base, most died when they encountered the automated robotic defense systems. Soon, only Grey and Harold remained of the original group. Harold was knocked out (he never did find out how) and woke up out in the desert looking exactly like a ghoul, yet not actually sharing the same trait as those meta-humans. Grey, however, was headed for bigger trouble. He had made it to the vats room, where massive bubbling cauldrons of the thick, green nutrient solution that contained the FEV waited to be used in experiments. Grey was accidentally knocked into a vat by an automated crane and managed to crawl out after a month. While the FEV was designed to be injected into humans, Grey soon found out that direct physical contact with the nutrient solution that it grew in worked just as well. He began to rapdily mutate in horrible ways, turning into a tentacled blob of mutated flesh. But he also developed potent psychic powers, which were enhanced by consuming other living minds to expand his own psionic strength. Slowly, as other Wasteland wanderers made it into the base over the months and years, he started doing his own experiments on human subjects with the FEV.

The Coming of the Master
Grey found that many of his test subjects were turning into giant, mindless brutes with the intelligence of a child, if they survived the mutational process at all. However, a rare few test subjects became the meta-humans known colloquially as Super Mutants. Immune to both disease and ionizing radiation and blessed with exceptional strength, intelligence, and endurance, Super Mutants were superior to pure strain humans in every way. They also possessed the exceptionally long life common to those individuals infected with FEV as well as (unbeknownst to Grey at the time) total sterility. Grey--who now called himself the Master--had long lamented the needless destruction of human civilization caused by the final nuclear holocaust of the Great War. In his warped state, he decided that he would have to force humanity to evolve beyond its own destructive impulses. If everyone could be as perfect as his Super Mutants, there would no longer be any reason for human conflict and the misery it wrought. Those who could not evolve along the lines the Master desired would have to die. The Master began seeking out uncontaminated pure strain humans in the Core Region Wasteland with which he could create new mutants and build his Super Mutant army.

However, creating new Super Mutants proved to be a hit or miss process. The great majority of Super Mutants produced by the Master and later his Lieutenant in the Mariposa Base's FEV Vats were big, dumb brutes. Physically, they were vastly superior to pure strain humans, but they possessed the intelligence of children. What exactly caused some mutants infected with FEV to be brilliant and the others to be child-like is unknown. The Master was certain this mutational randomness was related to the amount of radiation damage suffered by an individual: humans who had not been exposed to much of the post-nuclear environment's radiation produced more intelligent mutants after their FEV infection (see his personal diary for his thoughts on this). His Lieutenant, however, had a different theory. When the Chinese nuclear bombs hit the original West Tek Research Facility and turned it into the region known only as the Glow, the impact of the nuclear shockwave cracked open a few nutrient solution tanks filled with FEV. The nuclear bombs' radiation then mutated this FEV into an airborne strain of the original virus. But this new airborne strain of the FEV did not have any real mutagenic effects on human beings. All it did was inoculate any person infected with it against the original, mutational strain of the FEV, acting as a form of vaccine and giving exposed creatures some limited resistance to FEV's mutational effects. As a result, the ideal subject for FEV mutation was someone who had not been exposed to the airborne form of FEV following the Great War. Both of these conditions--no radiation exposure and no airborne FEV inoculation--were present in only one known population: Vault dwellers. Each Vault contained around 1,000 viable subjects who could be infected with the original strain of FEV and turned into highly-intelligent Super Mutants. Which factor exactly determines what would emerge from an FEV infection--accumulated radiation levels or inoculation by the airborne FEV strain--is still uncertain, though as a rule of thumb, the less exposed the subject is to radiation, chemicals and biological agents, the better.

In 2162, a person known as the Vault Dweller managed to kill the Master in his Cathedral beneath the ruins of Los Angeles and destroy the FEV Vats, and the Mariposa Military Base collapsed.

The Enclave and the Modified FEV Strain

 * Main article: FEV Curling-13

In 2236, the Enclave, the surviving remnant of the United States federal government, excavated the ruins of the Mariposa Military Base, largely using slave labor gathered from the town of Redding, and eventually discovered the remains of the Master's FEV Vats deep inside the lower levels of the base. Though they had been buried in rock and forgotten for long decades, the Vats still contained that old familiar green bubbling gunk, the nutrient solution that contained the living particles of the Forced Evolutionary Virus. The Enclave gathered samples to be sent back to the Oil Rig that served as their headquarters off the Pacific coast of California for further analysis. Before long, though, the slave miners, some being fully exposed to raw FEV in the course of the labors, others likely falling into the FEV Vats accidentally, began to mutate into a second generation of Super Mutants. The mutant slaves soon overthrew their Enclave guards. Seizing their weapons, hardware left behind by the first Mutant Army or anything lying around the ruins that could serve as a weapon, the Super Mutants stormed the upper levels and quickly overran the Enclave troops in the base. Panicked and retreating, the Enclave troopers on the upper levels fled the base and used explosives to seal the entrance, trapping the second generation mutants inside the base.

Still, even though things went poorly at Mariposa, the Enclave had the samples of FEV its scientists needed. Back at the Oil Rig, the Enclave's United States Chemical Corps began work on the serum immediately. They found that it would be possible to make from the FEV an incredibly potent and lethal viral toxin. Dr. Charles Curling was the Enclave scientist who lead this project under the direction of Dick Richardson, the President of the United States. But, in order for the research to progress, the Enclave needed test subjects. They required two test groups: one of uncontaminated, pure strain humans and another composed of the "mutants" that lived all over the mainland of the West Coast, who had suffered from nuclear radiation and airborne FEV exposure for decades. To the Enclave, this exposure made all the peoples of the Wasteland genetically impure, regardless of how similar in appearance they were to pure strain humans. The mutant sample was easily obtained when the Enclave's troops kidnapped the entire population of the town of Arroyo, who were all the descendants of dwellers from Vault 13, to see if they had suffered mutation after they left the Vault.

The pure strain human group proved difficult to obtain. The Enclave would not allow the Chemical Corps to use the Enclave's own people living on the Oil Rig (presumably because they were all too important to the Enclave's various projects). So, they had to look elsewhere. Once again, the mainland provided the needed stock. Thanks to the United States government's pre-Great War Vault Experiment project, the Enclave's scientists were able to determine that the pure strain population of Vault 13 was largely intact. Thus, the Enclave's troops traveled in force to Vault 13 and sent a command to the Vault's computers to open the Vault door. After taking care of some mild resistance from the surprised Vault dwellers, the Enclave's troops rounded up the residents of Vault 13 and shipped them off to the Oil Rig in Vertibirds to take part in the Chemical Corps' FEV experiments.

Before long, the Chemical Corps developed their viral supertoxin. It was found to be 100% lethal to humans who had suffered even mild radiation or airborne FEV exposure. Just as the Enclave was preparing to launch the poison into the North American jet stream to kill the entire population of the mainland, the Chosen One arrived at the Oil Rig on the Poseidon Oil tanker that had sat in the ruins of San Francisco for years. He freed the survivors of both the Vault 13 population as well as his own Arroyo tribals and started a self-destruct sequence on the Oil Rig that destroyed the entirety of the Enclave's headquarters, saving the surviving human population of the various American wastelands from a horrible death at the hands of the modified FEV strain - at least for a time.

The East Coast and FEV
In the Capital Wasteland centered on the ruins of Washington, D.C. on the East Coast of what was the United States, yellow-skinned Super Mutants had also appeared along with a modified version of the chimaeric mutants known as Centaurs. It was eventually learned that a modified version of the FEV was to blame for the emergence of these version of the Super Mutants and the Centaurs on the East Coast. In the Capital Wasteland, Vault 87 had been equipped with a large supply of the FEV. In 2077, following the fall of the Chinese nuclear bombs on Washington, D.C., the dwellers of Vault 87 had been forcibly infected with a modified version of the FEV as a part of the secret Vault Experiment project controlled by the U.S. government and the Vault-Tec corporation. The modified version of the FEV used in Vault 87 gave the skin of the Super Mutants it created a yellow tint and made these mutants stronger and larger as they aged while greatly lowering their intelligence. This version of the virus also seemed to create more "healthy" Super Mutants than their Core Region counterparts, who were much more mutilated by the virus-induced mutations as a result of the Master's modifications. However, in the Capital Wasteland highly intelligent Super Mutants developed much less frequently, with only two "civilized" Super Mutants encountered in Fallout 3, including Uncle Leo and Fawkes. Once in Vault 87, the Lone Wanderer can overhear a conversation between two Super Mutants where they discuss collecting stronger men to become stronger Super Mutants, by putting them in "the green stuff". This is thought to be the reason for the Super Mutant Captives strewn across the Capital Wasteland who are captured as opposed to being killed and eaten by their Super Mutant captors, as the Lone Wanderer hears from various NPC conversations and Three Dog's radio broadcasts. Uncle Leo also mentions that Super Mutants periodically abduct humans to create more Super Mutants using their diminsihing supply of FEV located in Vault 87.

The Enclave's President John Henry Eden attempted to convince the Lone Wanderer to use the same modified form of FEV originally developed thirty years earlier by the Enclave on the West Coast to taint the activation of the Purifier. Like its predecessor this strain of the FEV had been created by the Enclave to kill all forms of life with any degree of radioactive or virally-induced mutation. If the Lone Wanderer carries out Eden's plan, then in the Broken Steel add-on you will find that the Wastes are devoid of those that had hoped to find new beginnings with the cleansing of the water of the Potomac River. You will receive purified waters tainted with the modified FEV and can give these to beggars to lose karma and kill them.

FEV Variations
At least four different variations of the post-Great War FEV are known to exist, plus one rumored. The FEV is a major cause of mutations in all of the Fallout games, and usually is an instrument used by a villain to achieve his goals.

Mariposa FEV strain
The original strain of the virus that was developed at the Mariposa Military Base and later gave birth to the Master, Unity and the army of the West Coast Super Mutants. All the Super Mutants presented in Fallout, Fallout 2, Fallout Tactics and Fallout: Brotherhood of Steel were created using this strain, including Frank Horrigan, who was further augmented and experimented on by the Enclave's scientists. other notable mutation creatures created by infection with this virus are Centaurs, Floaters, and two ghoul-like mutants: Harold and Talius. The Master desired to use this virus to remake humanity into his own twisted vision of perfection.

Vault 87 FEV strain
This modified strain of FEV was located in Vault 87 in the Capital Wasteland and was also responsible for the creation of a Super Mutant army, this time the forces of the Capital Wasteland's Super Mutants. This strain completely wiped out any signs of pre-mutation gender and, compared to its western counterpart, produces quite different creatures, who grow bigger as they age. This FEV strain is used by the Super Mutants to produce more of them in Vault 87. This FEV strain, like the Mariposa version, gave birth to a group of misshapen mutants known as centaurs.

FEV Curling-13 strain
The Enclave, while led by President Dick Richardson, developed their own version of the FEV. It was an airborne modification that was intended to be spread by Vertibirds into the North American jet stream so that it could infect the entire American mainland. Created by the Enclave scientists led by Dr. Charles Curling, this strain of the virus was designed to kill all the "mutant" inhabitants of the post-nuclear United States.

Eden's FEV strain
When the Enclave relocated to the Capital Wasteland after the destruction of its oil rig headquarters off the coast of California in 2242, the survivors of the Oil Rig's destruction probably brought a sample of Richardson's modified Curling-13 strain of the FEV with them. President Richardson's successor as the leader of the Enclave, President John Henry Eden, a sentient artificial intelligence, personally remastered the virus, and altered it so that it was water-soluble instead of airborne. The president planned to use it to continue Richardson's plan to wipe the United States clean of all mutants, this time using Project Purity, an independent effort intended to cleanse the Potomac River of its radioactive contamination and restore clean water to the people of the Capital Wasteland.

Vault-Tec's FEV strain
In Fallout: Brotherhood of Steel, a secret Vault-Tec installation known as the Secret Vault was uncovered by the Super Mutant remnants of the Master's army, who were led by a very strong and highly intellegent Super Mutant named Attis. It was revealed that Vault-Tec's scientists had intended to further improve the FEV (which they had acquired while building Vault 87 for the United States government). They wanted to use the virus as both a bio-weapon and as a key to humanity's evolutionary future, which is why they were determined to overcome the virus' primary disadvantage--the sterility it produced in mutants infected by it. They proved unsuccessful in making FEV mutants fertile, however. But the resulting modifed Vault-Tec FEV strain provided mutants infected with new features like even faster cell regeneration. The living bio-weapons created by this modified FEV probably included the unusual species of Radbugs native to Texas, and the horrifying experimental deathclaws. When Attis, who already transformed into a Super Mutant by that time, used the modified strain on himself, he started to regenerate even more rapidly and grow much larger, eventually becoming a giant, rapidly multiplying, multicellular organism, which was destroyed by an explosion.

Appearances in games
FEV appears in some form in all Fallout games.

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