Photo: 20th Television

The Most Important Episodes Of 'The X-Files'

Voting Rules
Vote up the episodes that mattered most to the series overall.

Decades before TV viewers could stream series with complex, seasons-long, and bingeworthy narratives, Chris Carter's The X-Files carved out a unique niche. His show introduced a more consistent "monster-of-the-week" format situated within an overarching narrative mythology. Casual viewers could tune in for a weekly dose of frights without too much character or plot baggage attached, and dedicated fans were rewarded for their attentiveness with plots and sub-plots linking characters, locations, and objects throughout the show's run.

For 202 episodes and nine seasons - plus two feature films and two encore seasons - FBI Special Agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) chased lights in the sky, fought terrifying cryptids, and attempted to deny their love for one another while pursuing a truth that remained forever out of reach.

While some episodes were pedestrian, others were nightmare-inducing, but all were essential parts of the larger tapestry of one of the best series in TV history. Vote up the episodes of The X-Files that mattered most to the series overall.

Photo: 20th Television

  • 1
    186 VOTES

    Pilot (Season 1, Episode 1)

    The series pilot introduces Fox Mulder and Dana Scully and establishes them as believer and skeptic, respectively - a dynamic that becomes the signature of their relationship for much of the series. The pilot also introduces aliens - and the government's perceived cover-up of their existence - as a primary motivator behind Mulder's pursuit for the truth. 

    This first episode also sets up William B. Davis as the Cigarette Smoking Man, the series's antagonist and primary obstacle to uncovering that truth.

    The pilot was generally well-received by critics, with Variety praising the dialogue as "fresh" and the characters as "involving," in a series premiere that "kicks off with drive and imagination."

    186 votes
  • 2
    140 VOTES

    The Erlenmeyer Flask (Season 1, Episode 24)

    In the Season 1 finale, Fox Mulder and Dana Scully discover evidence of a secret government experiment involving alien DNA. Tipped off by Deep Throat (Jerry Hardin), Mulder and Scully investigate the mysterious end of a green-blooded doctor, as well as that of another doctor connected to the case who seemingly took his own life. 

    Scully's characteristic skepticism waivers when fellow scientist Dr. Anne Carpenter (Anne De Salvo) analyzes the contents of an Erlenmeyer flask discovered by Mulder and declares the contents extraterrestrial in origin. Scully sneaks into a government facility where she discovers the proof they've been looking: an alien fetus frozen in liquid nitrogen.

    By the episode's end, the status quo is shattered as Mulder and Scully's informant, Deep Throat, perishes after uttering "Trust no one," and the X-Files division is shuttered by the FBI.

    140 votes
  • While investigating the passing of several psychics and fortune tellers, Fox Mulder and Dana Scully receive the assistance of Clyde Bruckman (Peter Boyle), a psychic with the ability to see a person's demise before it occurs.

    Scully is dubious of Bruckman's abilities, especially after he tells her that he will share an emotional moment with her in bed, but his premonition of Mulder's end at the hands of a serial killer helps Scully arrive in the nick of time to save her partner's life. When they seek out Bruckman to tell him they have stopped the culprit, they find that he has taken his own life. Scully sits on the bed next to Bruckman and holds his hand, fulfilling his earlier prophecy.

    While this episode is not particularly integral to the greater mythology of the series, it is a vital episode for the show's health as a whole, and it is consistently regarded as one of the best episodes of the entire series.

    TV Guide rated it the 10th greatest episode in television history, and Vulture named it the best episode of The X-Files.

    177 votes
  • When Dana Scully learns she has a cancerous tumor, Fox Mulder becomes convinced that her illness was caused by a government conspiracy and her prior abduction in Season 2. While Scully begins chemotherapy, Mulder investigates the ends of Mutual UFO Network (MUFON) members who were diagnosed with symptoms similar to Scully's.

    Mulder discovers a doctor working alongside a group of human-alien hybrid clones. The clones reveal that Scully and the other women were their surrogate mothers in a planned colonization project. Mulder takes back Scully's ova and returns to her side at the hospital as she fights her illness.

    While this episode had its detractors, it was well-received overall. The A.V. Club gave it an A, calling it "occasionally beautiful, occasionally haunting." It was submitted for a Primetime Emmy Award and likely contributed to Gillian Anderson winning a Primetime Emmy Award for Outstanding Lead Actress in a Drama Series.

    123 votes
  • 5
    178 VOTES

    Squeeze (Season 1, Episode 3)

    Aliens take center stage in the first two episodes of Season 1, and they remain the underlying motivator behind the creation and continued existence of the FBI's X-Files division. "Squeeze" introduces the first of the series's "monster-of-the-week" standalone episodes. The episode was also responsible for hooking many viewers who were initially skeptical of the series.

    The episode introduces Doug Hutchison as Eugene Victor Tooms, an ancient mutant serial killer capable of squeezing into impossibly tight spaces to commit his deeds.

    The episode was well-received, with Entertainment Weekly calling it "important" and the Vancouver Sun declaring it "one of the scariest things... ever seen on television."

    178 votes
  • 6
    119 VOTES

    Anasazi (Season 2, Episode 25)

    Fox Mulder receives a tape containing top-secret Defense Department files related to extraterrestrial life, but he finds it unreadable. Dana Scully, believing the code encryption is based on the Navajo language, goes in search of a Navajo translator, ultimately giving the tape to Navajo elder Albert Hosteen (Floyd Red Crow Westerman). Earlier in the episode, Hosteen was gifted alien remains found in a buried boxcar.

    Meanwhile, Mulder faces dismissal from the FBI for his increasingly erratic behavior and his accosting of Assistant Director Walter Skinner. Mulder then embarks on a mission of vengeance to end his former partner Alex Krycek (Nicholas Lea) for taking the life of his father.

    Scully prevents Mulder from taking out Krycek and secrets him away to New Mexico, where she reveals his behavior was caused by substances placed in his drinking water. She also shares that the tape contains information about her and Duane Barry. Mulder is led to the location of the boxcar - which still contains the remains of several creatures - and is seemingly eliminated by the Cigarette Smoking Man's commandos, who set the boxcar on fire.

    The Season 2 finale is filled with lore that drives the show's mythology for the remainder of the series. While it's hard to believe that Mulder actually perished, his father's demise proves that anyone besides the two leads are fair game. Krycek is also positioned as a formidable adversary.

    119 votes