Special Agents Fox Mulder (played by David Duchovny) and Dana Scully (played by Gillian Anderson) investigate unsolved cases that are often beyond explanation. These cases are called the X-Files. They find themselves on a constant search for the truth.
The fourth season involves the illness of someone close to Fox, the murder of the mysterious Mr. X (played by Steven Williams), the return of Alex Krycek (played by Nicholas Lea) and a health crisis for Scully. Rather than discourage or distract Mulder this strengthens his belief in the existence of alien life and the subsequent cover up by the American government.
Episode 1: Herrenvolk: Mrs. Mulder (played by Rebecca Toolan) is very ill and Mulder will go to any lengths to save her. Part of his plan is to keep safe the healer Jeremiah Smith (played by Roy Thinnes) from the alien bounty hunter (played by Brian Thompson).
Episode 2: Home: In a small, quiet town the agents are called in when the body of an infant with a multitude of birth defects is found. The clues lead to an inbred family that has lived secluded in their house for generations.
Episode 3: Teliko: A series of black men turn up missing then dead with their bodies devoid of any pigmentation. Mulder and Scully are on the trail of a killer who is African and might need human hormones to survive.
Episode 4: Unruhe: Mulder and Scully work a case involving a killer who leaves clues in psychic photographs. The pictures reveal the killer’s darkest fears and fantasies.
Episode 5: The Field Where I Die: Mulder and Scully work on a case involving a religious cult. While working on the case Mulder comes in contact with a woman he begins to believe he knew in a previous life.
Episode 6: Sanguinarium: A series of murders happen at a well-known hospital and the oddness of them brings Mulder and Scully in on the investigation. It seems like a plastic surgeon working there is involved in black magic.
Episode 7: Musings of a Cigarette Smoking Man: The life story of Mulder and Scully’s nemesis is divulged. His story is linked with the assassination of JFK and the cover up at Area 51.
Episode 8: Tunguska: A strange rock is uncovered that contains a deadly viscous organism. It is up to Mulder and Scully to uncover the origin of the rock.
Episode 9: Terma: Mulder finds himself working with Alex Krycek while trying to determine the origin of the rock. It is while doing so that he realizes the depth of Krycek’s deception.
Episode 10: Paper Hearts: Mulder begins having dreams about an old case involving a serial killer start coming true. After reopening the case he discovers that one of the missing young girls might be his sister Samantha.
Episode 11: El Mundo Gira: A death of a woman in a Mexican migrant camp draws the attention of Mulder and Scully. The case turns to involving a mythical Mexican creature known as “El Chupacabra”.
Episode 12: Leonard Betts: A paramedic who was declared dead after being decapitated in a car crash seems to have somehow come back to life. Mulder thinks it is possible because of his ability to regenerate himself somehow.
Episode 13: Never Again: Scully feels dissatisfied with the course of her life. With Mulder off on a forced vacation, Scully begins seeing a man and gets a tattoo.
Episode 14: Memento Mori: Scully attempts to come to terms with the fact that she has inoperable cancer. In order to try and find the cure for Scully’s cancer, Mulder and the Lone Gunmen break into a high-security research facility.
Episode 15: Kaddish: Mulder and Scully work on a case involving a hate crime within the New York Hassidic community. As the case develops it appears that a series of murders might have been committed by a dead man.
Episode 16: Unrequited: An assassin who seems to have been able to disappear into thin air has managed to murder a couple of high ranking military officers. Mulder and Scully are charged with capturing the invisible man.
Episode 17: Tempus Fugit: The agents are put on the case of the unexplained crash of a commercial airliner. While investigating they are led to a lake and what they discover is shocking.
Episode 18: Max: Mulder and Scully work on the crash leads them to the pursuit of an angle that the plane was purposely crashed in order to destroy stolen technology. Mulder then thinks that the plane went down due to an alien vessel.
Episode 19: Synchrony: Several research scientists are found frozen to death and Mulder and Scully are called in to get to the bottom of things. Mulder begins to believe that the murderer is a time traveller from the future.
Episode 20: Small Potatoes: In a small-town several babies are born with vestigial tails. The father turns out to be a man who has the ability to impersonate anyone even Mulder.
Episode 21: Zero Sum: Assistant Director Skinner (played by Mitch Pileggi) finds himself trapped by a deal he makes with Cigarette Smoking Man (played by William B. Davis) in order to save Scully’s life. He destroys evidence in a fatal bee death and ends up framed for murder.
Episode 22: Elegy: The ghostly images of young women begin appearing to people just before they are murdered. Mulder begins to believe they are warnings of their own upcoming deaths to the people who see them.
Episode 23: Demons: Mulder wakes up in a Rhode Island motel covered in blood and doesn’t remember how he got there. As he and Scully try to piece together his last few days they stumble upon the trail of a double murder.
Episode 24: Gethsemane: Mulder fights to prove that something found in the ice in Canada is irrefutable evidence that aliens exist. His investigation leads to something he could have never expected.
- Deleted Scenes
- Extended Scenes
- Special Effects with Commentary by Paul Rabwin
- Deleted Scenes (w/optional commentary by Chris Carter)
- Tunguska – Interview With Chris Carter
- Paper Hearts – Interview with Vince Gilligan
- Memento Mori: Audio Commentary by Rob Bowman
- Introduction to Memento Mori by Chris Carter and Frank Spotnitz
- Max: Audio Commentary by Kim Manners
- Documentary: “The Truth About Season Fou