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Black oil or Purity in 35,000 B.C..

Purity, more commonly referred to as black oil, and called "the black cancer" by the Russians, was an alien virus that thrived in petroleum deposits underground on Earth. The virus was capable of entering humanoids through their eyes, mouth, nose, and ears and assuming control of their bodies. It was sentient and was capable of communicating. It is the "life force" of the alien colonists, which they seemingly use to reproduce their kind, as well as infect other alien races in order to conquer the universe. (TXF: "Piper Maru", "Two Fathers", "The Truth")


Early Human Contact[]

According to the Well-Manicured Man, black oil was the original inhabitant of the planet Earth.

In 35,000 B.C., two primitive humans pursued a set of strange tracks through the frozen wasteland that was North Texas. They followed the tracks into a cave, where they were attacked by a long-clawed alien that had left the tracks. Although one of the men was killed, the other managed to injure the creature. As the alien lay dormant on a rock, black blood poured out of its body, covered the remaining man and painfully infected him. (The X-Files Movie)

In 1945, a squadron of P-51 Mustang airplanes escorted a B-29 transporting a nuclear bomb similar to those used on Japan during World War II. However, the B-29 and its accompanying squadron of aircraft crashed in the Pacific Ocean after they had a hostile encounter with a UFO that also crashed.

The black oil pours out of Captain Kyle Sanford aboard the Zeus Faber in 1945.

Later the same year, an American submarine named the Zeus Faber was deployed in an attempt to locate the crash site. The Zeus Faber found the sunken squadron but the submarine's crew also unknowingly brought the black oil aboard. The alien substance possessed the Zeus Faber's commanding officer, Captain Kyle Sanford, and manipulated him into refusing to return to port without providing an explanation.

When the crew turned on the possessed captain and rendered him unconscious (or possibly killed him), the alien entity left his body and then seemingly the submarine itself, returning to the ocean. The Zeus Faber's crew complement had been 144 when it left port, but only seven survived the return journey to Pearl Harbor. The majority of the crew had died from radiation burns due to exposure to the possessed Captain Sanford, though none of the crew were ever given an explanation for the awful burns and the survivors never discovered a reason for their own survival. The incident was never revealed to the public. (TXF: "Piper Maru", "Apocrypha")

The Piper Maru Incident[]

In 1995, the UFO that had crashed with the squadron of US airplanes was recovered by an American salvage ship named the Talapus. (TXF: "Nisei") While the UFO was secretly taken to San Diego and secured within a guarded warehouse there, the black oil remained within the Pacific Ocean. (TXF: "Nisei", "Piper Maru")

Bernard Gauthier infected with the alien black oil.

In 1996, the French salvage ship Piper Maru was on a mission to locate the sunken squadron of airplanes when a diver, Bernard Gauthier, discovered one of the planes. The Piper Maru's crew had been monitoring Gauthier's progress when they lost all contact with him. Gauthier continued to inspect the plane and found that a pilot was bizarrely still alive inside, trapped in the cockpit and possessed by the black oil. By the time Gauthier returned to the surface of the water and was recovered by the Piper Maru, he had also been possessed by the alien substance. Gauthier claimed that he was unharmed and asked his crew mates to help him remove his diving suit. One man found a thin layer of oil that covered the diving suit but thought nothing sinister of it. Like the men aboard the Zeus Faber, the black oil also exposed the crew of the Piper Maru to extremely high levels of radiation. The ship slowly journeyed to San Diego, steered home by the possessed Gauthier - the only man not affected by the radiation.

The French government classified the nature of the contaminant that had irradiated the Piper Maru's crew and refused to release that information. In fact, the US Navy inspected the Piper Maru but found nothing unusual nor any radiation aboard the vessel.

The crew members suffering from the radiation were admitted to San Diego Naval Hospital but determining a course of treatment for their deteriorating condition was complicated by the secrecy regarding the incident. What could be determined was that the men had been exposed to an unnaturally high level of radiation, with a high rate of absorption. Symptoms included spontaneous internal bleeding in the mouths and intestinal tracts, blood in the urine and severe delirium — the pre-advanced stages of a coma. Though Gauthier had been held at the hospital for one day, he seemed to be in very good health and discharged himself the next morning.

Joan Gauthier infected with the black oil.

Gauthier, controlled by the black oil, returned to his home in San Francisco, California, where he lived with his wife, Joan. (TXF: "Piper Maru")

Outbreak in America[]

In late 1996, a diplomatic envoy from Russia landing in Hawaii was intercepted by security guards and searched for acting suspiciously with them. During the search, the guards discovered a canister containing what the envoy described as a biohazardous material. The guard dropped the canister, shattering it and releasing its contents: Purity.

Another envoy carrying a sample of the same rock from Tunguska, Russia, arrived at Dulles International Airport in Washington, D.C.. With the ironic assistance of Alex Krycek, Agents Mulder and Scully attempted to intercept the courier. However, he fled but dropped his diplomatic pouch that contained the mysterious rock. Krycek knew that the Syndicate would be looking for the rock, and he was eager to take revenge against the Cigarette Smoking Man. Krycek was then kept in Walter Skinner's apartment while Mulder and Scully tried to learn more about the rock. The CSM approached Skinner the following day demanding to know the whereabouts of the pouch, but Skinner was unable to answer because the agents hadn't revealed it to him. Scully took the rock to the NASA Goddard Space Flight Center to have it analyzed with Dr. Sacks. Sacks discovered that the rock was made of the same as material as meteorites, which prompted Mulder to travel to Tunguska in search of answers.

Mulder and Krycek traveled to Russia, where they discovered prisoners of a gulag mining for extraterrestrial rocks like the one they had intercepted. However, they were discovered and imprisoned. Betrayed by Krycek yet again, Mulder was then subjected to an experiment wherein he was exposed to the black oil. However, he survived unscathed because the Russians had developed an effective vaccine. Meanwhile, the Russians discovered the outbreak in the United States. Vassily Peskow was sent to take care of it. Ultimately, Peskow successfully covered up the presence of the black oil and destroyed much of it by blowing up an oil well in North Dakota. (TXF: "Tunguska", "Terma")

The Vaccine[]

In 1997, Alex Krycek discovered a boy who witnessed the burnings of a group of abductees by the faceless alien rebels. In order to ensure that no one else found out what happened, Krycek infected the boy with the black oil and brought him to the United States, to barter him with the Syndicate. He also managed to smuggle a sample of the vaccine that the Russians developed, which he gave to the Syndicate. They tested it successfully on Marita Covarrubias, who had been infected with the virus by the boy. (TXF: "Patient X", "The Red and the Black")


In 1998, several people were infected with a strain of the virus lying dormant beneath suburban Dallas, Texas. The Syndicate, fearing an outbreak, hastily tried to contain the virus, and learned that it not only inhabits and controls its host, but also uses it as an incubator for a new alien life-form. Agents Mulder and Scully investigated the deaths of the infected people, and were led to a site where genetically-modified corn pollen was being harvested in order to carry the virus, which will be delivered by bees during the alien invasion. Scully is later stung by one of the bees, and infected with the virus. The Syndicate abducted her and took her to a research facility in Antarctica, where she is incarcerated along with hundreds of other infected hosts. Mulder pursued her and was able to administer a vaccine to her, which had been provided by Well-Manicured Man. (The X-Files Movie)

Galpex Orpheus Incident[]

The black oil leaving Krycek.

In 2001, the black oil was encountered again. The Galpex oil company ran an oil rig in the Gulf of Mexico that tapped a petroleum reserve containing the virus, infecting the entire crew. Simon de la Cruz and Diego Garza were remarkably immune to the virus. Simon was killed by Bo Taylor after he attempted to contact the mainland and Garza went into hiding aboard the rig. Fox Mulder, who had recently reappeared following his abduction, brought the FBI into the situation after Simon's corpse washed ashore in Texas. Furious that Mulder had gotten the Bureau involved, Alex Krycek sent John Doggett to clear everything up. However, Mulder disobeyed orders and traveled to the rig on his own, beating Doggett there. With help from Scully back in Washington, Mulder was able to confirm that the black oil was indeed present aboard the rig. Doggett was nearly killed by Taylor as well and was able to witness the virus for himself. As Mulder and Doggett attempted to contact the mainland, the infected crew members tried to kill them - but they stopped as soon as Mulder destroyed the radio. Almost at once, the crew then tried to blow up the platform, but the agents were rescued before it went up in flames completely. Although Mulder took the fall for the destruction of the platform, he exhorted Doggett to keep Galpex from continuing operations on the virus-infected oil reserve. ("Vienen")

The Black Oil going back into its ship

Questionable Information[]

A theory concocted by doctor Sacks and FBI Special Agent Dana Scully is that the black oil came to Earth prehistorically on a meteor from Mars that also carried the first building-blocks of life to Earth. The virus then thrived on Earth and infected primitive humans, completely changing their physiology and transforming them into alien life-forms themselves. In the planet's last ice age, these aliens died and the virus lay dormant underground until it resurfaced during Earth's current geologic period.

The same theory states that, in 1947, a UFO crashed in Roswell, New Mexico. The virus communicated with the UFOs, alerting the American government to its presence.

Unfortunately, there is insufficient evidence to prove Scully's theory. (TXF: "The Truth") The UFO crash that apparently took place in Roswell is also unprovable, although there are historical reports of the alleged incident. (TXF: "Deep Throat") There is also evidence that human life actually originated from another extraterrestrial source, whose spacecraft is submerged on the Ivory Coast in Africa. (TXF: "Biogenesis")

There are contradictory statements made in regards to what the Black Oil actually is, as some remarks in Apocrypha and Vienen indicate that the substance is actual oil, with the virus inhabiting it, while other episodes indicate it's simply a black vermiform organism that only appears to be oil until it begins to infect the host, upon which it takes a worm-like appearance. It is unknown if the black oil is actually the alien blood as seen in the movie Fight the Future.

The relationship between Purity/colonists and Alien Bounty Hunters is also unclear (parasitic and/or symbiotic relationship, same or distinct species). According to "The Truth" and other episodes the bounty hunters are infected with black oil virus, but we do not see black oil in their eyes, unlike infected humans, which suggests that the nature of the infection may be different. It is also unanswered, that bounty hunters why they have not defended themselves against black oil, while the faceless rebel aliens sealed all openings in their faces, to protect themselves from infection. (TXF: "The Red and the Black")

Abilities and Effects[]

  • The Black Oil has demonstrated a wide variety of abilities and behaviors. It is seemingly able to survive long periods of time in extremely adverse environments, such as underwater and extreme cold, with some evidence to suggest that cold forces it into some sort of hibernation or remission.
  • Certain genetic mutations in various individuals make them immune to the virus, and if it attempts to infect them it will die.
  • The alien virus has the apparent ability to penetrate various forms of matter such human skin, high-level protective equipment suits or even metallic surfaces. However, a complete sealing of the orificies of a biological entity proved to be effective to avoid infection with the virus, as demonstrated by the faceless alien resistance fighters.
  • People infected with the alien virus demonstrate a variety of symptoms/abilities. Some are taken over by it, indicating that it possesses some sort of intelligence and that they know its purpose. Those infected are capable of producing a flash of extremely deadly radiation. Others who have been infected instead enter a comatose state, possibly in preparation for gestation of an alien life form. Some infected hosts display a telltale trait—black clouded eyes.
  • When infected with the form of the virus spread by the bees, the host often feels extreme discomfort due to being cold. Given that the virus needs heat, this prompts them to seek heat to accelerate gestation.
  • Another form of the virus, the super soldier form, puts the host in to a near death state while it grows a "replacement" inside them, which later emerges by means of shedding the previous skin.
  • Some individuals exposed to the black oil will also experience unusual effects in the presence of certain alien spacecraft, as Mulder did in Biogenesis. (A number of questions regarding this were never answered, such as why Scully, who was also exposed to the virus, did not experience the same effects. It is also unclear if all alien spacecraft of this type, such as the one in Providence, are capable of causing these effects, or only the one found off the Ivory Coast possessed this ability.)
  • The black oil form of the virus can willingly abandon its current host and leap to another, or simply go in to hiding. Once the host no longer has the virus in their system, they seem to lack any memory of events that occurred while they were under the infection of the virus.

The fact that all of these forms of the virus are susceptible to the vaccine, created by the Syndicate and the Russians, indicate that they are all one and the same, or simply variations of the same organism. Being that the black oil itself dates back tens of thousands of years, or more, the latter two versions of virus are likely artificial modifications, made by the Syndicate and the colonists/bounty hunters, respectively.


The pregestational symptoms include a blackening of the eyes and the appearance of something crawling up the body as well as a sensitivity to cold prior to gestation.

Strategy for Fighting Purity in The X-Files: Resist or Serve[]

The Purity in its true form can't be defeated. Mulder or Scully must run away from it - an easy feat due to its slow speed. However, if Purity catches up to them and touches them, they will become a host for it, forcing the player to restart the mission.


The following is a list of individuals who were infected with the black oil. Each host was temporary and did not gestate into a vicious alien, unless stated otherwise.

Background Information[]

Some fans of The X-Files have speculated that the original concept of the black oil virus may have been influenced by a parasitic ice worm that featured in the Season 1 episode "Ice". Although none of the series' production staff have admitted or denied this possibility, the two concepts do share several similarities. In the episodes they are featured in, suggestions are made that both lifeforms came to Earth from space via a meteor. They are also both seen to infect their hosts and manipulate their hosts' behaviors, creating a mood of paranoia. Additionally, one of the parasitic worms in "Ice" can be seen squirting a black, oily substance in a scene where it is extracted from a human host. This substance is referred to as being a poison but it does look similar to the black oil.

The second of four DVD collections in The X-Files Mythology series is named "Black Oil" and includes several early episodes that feature the alien substance.

Appearances & References[]

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