At the end of fourth season, Scully is dying of cancer. Mulder is convinced that her condition is a result of her earlier abduction, and is prepared to make a deal with the Syndicate to find a cure. While being pursued by an assassin responsible for a hoax alien corpse discovered on a mountaintop, Mulder fakes his own suicide, mutilating the assassin’s face to provide a decoy body. In the fifth season opener “Redux”, he uses the distraction this offers to infiltrate The Pentagon to find a cure for Scully’s cancer, while Scully is able to uncover and reveal a Syndicate connection within the FBI. Due to the information he learns from Michael Kritschgau (John Finn), Mulder loses his belief in extraterrestrials. Later, as a rebel alien race secretly attacks several groups of former alien abductees, the agents meet Cassandra Spender (Veronica Cartwright), a woman who claims to be a multiple abductee and wants to deliver a positive message about aliens. Eventually, Mulder has Scully put under hypnosis to learn the truth about her abduction after Cassandra goes missing and her son,Jeffrey Spender (Chris Owens), angrily attempts to push his way up in the FBI. The Syndicate, meanwhile, quicken their tests for the black oil vaccine, sacrificing their own to do so. Later, the assassination of a chess grandmaster leads Mulder and Scully into an investigation that they soon discover strikes at the heart of the X-Files; they learn that the real target was a telepathic boy named Gibson Praise (Jeff Gulka).
This season has a lot of stand out episodes which make it the best season overall. The origins of the Lone Gunmen are explored. In 1989, two salesmen and a federal employee join forces when they meet Susanne Modeski, a woman who claims that she is being pursued by her violent ex-boyfriend, an FBI agent named Fox Mulder. We learn how agent Mulder came to meet three friendly and familiar faces. On the way to an FBI convention in Florida, Mulder and Scully stop to help in the investigation of the mysterious disappearance of three people in the woods, where a pair of invisible humanoids lurk. Filmed in black-and-white, Mulder and Scully’s investigate a letter from a single mother that leads them to a small town where a modern-day version of Frankenstein’s monster lurks, Jerry Springer is an obsession, and Cher plays a significant part. Home for the holidays, Scully is haunted by dreams which hint at a strange connection to a murdered woman’s daughter. Scully fights to protect her daughter’s life, while Mulder discovers her true origins. When ‘Pusher’ Modell escapes from prison, Mulder and Scully race to catch him before he can take revenge against his favorite target – Agent Mulder. When a teenager is suspected of murdering his father, Mulder and Scully become convinced that a greater evil may be lurking in the community. Scully takes a vacation to Maine, where she encounters a bizarre case where the victims appear to have inflicted wounds upon themselves – apparently at the behest of a strange young girl. This episode was co-written by famous horror writer Stephen King. It carries the alternate title of “Bunghoney” in some sources.
While investigating the strange circumstances of the death of a reclusive computer genius rumored to have been researching artificial intelligence, Mulder and Scully become targets of an unlikely killer capable of the worst kind of torture. The episode was co-written by cyberpunk pioneers William Gibson and Tom Maddox. While investigating bizarre exsanguinations in Texas, Mulder kills a teenage boy whom he “mistakes” for a vampire. Awaiting a meeting with Skinner, Mulder and Scully attempt to get their stories “straight” by relating to each other their differing versions of what happened during their investigation. In 1990, a bizarre murder leads young agent Fox Mulder to question a former FBI Agent who investigated one of the first X-Files dating back to the 1950s – a case which may have involved Mulder’s father. Agents Mulder and Scully investigate a murder that seems to have been committed by a blind woman, but Mulder suspects that her involvement is not what it seems. The unexplained death of a young handicapped girl prompts Father McCue to ask Scully for her help, but her investigation leads her to a mystery she’s afraid to understand. Scully begins to grow suspicious of Mulder, whose increasingly strange behavior suggests he may be serving another agenda. Mulder and Scully encounter a delusional man who believes his boss may be a monster – and is willing to pay any price to prove it. Investigating the murder of a chess player, Mulder and Scully meet a boy who may be the embodiment of everything in the X-Files. This episode marks the first appearance of Diana Fowley (Mimi Rogers).
This was the last season to be shot in Vancouver and the production was moved to Los Angeles.