Mulder travels to Puerto Rico on the advice of his Senate mentor, to uncover the reason behind the sudden reactivation of a communications station.
Mulder discovers a human parasite using the sewer system as its home.
Mulder and Scully investigate a series of violent murders committed by seemingly ordinary residents of a small town.
Mulder and Agent Krycek attempt to uncover the killer's plot.
A former FBI agent claims he was abducted by aliens.
Mulder and Krycek race against time to find and rescue the kidnapped Scully.
While Agent Scully remains missing, Agent Mulder embarks on a vampire investigation in Los Angeles.
Scully is found in a coma at a local hospital, her life hanging in the balance.
In a remote location, scientists watch as their camera captures a moving shadow inside a hot, smoldering volcano.
The team discovers a vegan religious cult accused of kidnapping local teenagers to perform some sort of ritual.
Mulder links a series of violent attacks including the brutal rape of a nurse to angry spirits beyond the graves.
A pregnant woman suffers from visions that lead her to the remains of two FBI agents who went missing in the 1940s while on a mission to catch a serial killer.
Scully and Mulder hunt down a fascist who is collecting dead bodies.
The agents investigate a murder in a small town inhabited by Satanists.
The death of a Marine who allegedly committed suicide reveals a disturbing truth in a Haitian refugee camp.
Things take an unexpected turn when Mulder receives a call from his father.
Mulder is forced to make an impossible choice when an alien bounty hunter gives him an ultimatum.
In a small Idaho town, a man is killed by what appears to be an invisible elephant. At the local zoo, Mulder discovers evidence of strange experiments.
The crew of a US military ship that disappeared in the Norwegian Sea is found dead.
The agents search for a killer in a Florida town populated by artists.
The agents open an investigation when a young boy's family suffers a series of tragic accidents.
While Scully investigates a deadly infection spreading through the prison, Mulder tracks down two escaped convicts who are infected with the disease.
Mulder meets a former student of Scully's, and he realizes that the man is afraid of his own shadow for some reason.
The employees of the Chaco Chicken Foundation are exhibiting strange behavior, and the death rate is slowly increasing.
Mulder receives an encrypted computer disk containing secret the defense department's top-secret files on extraterrestrial life.