instruction: What is The Sixth Extinction (The X-Files)?
context: "The Sixth Extinction" is the first episode of the seventh season of the science fiction television series The X-Files. It was first shown on the Fox network on November 7, 1999, in the United States. The episode was written by Chris Carter and directed by Kim Manners. "The Sixth Extinction" earned a Nielsen household rating of 10.6, being watched by 17.82 million people in its initial broadcast. The episode received mixed to positive reviews from critics.
  
  The show centers on FBI special agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) who work on cases linked to the paranormal, called X-Files. Mulder is a believer in the paranormal, while the skeptical Scully has been assigned to debunk his work. In the episode, Assistant Director Walter Skinner (Mitch Pileggi) and Michael Kritschgau (John Finn) work desperately in an attempt to discover what is wrong with Mulder, whose abnormal brain activity has rendered him imprisoned in his own head, but they are unaware of Agent Diana Fowley’s (Mimi Rogers) duplicity. In the meanwhile, Scully is hunting for an ancient artifact in Africa.
  
  "The Sixth Extinction" helped to explore new aspects of the series' overarching mythology and was the second episode in a trilogy of episodes featuring Mulder's severe reaction to the appearance of an alien artifact. The episode was written due to series creator Chris Carter's fascination with the possibility that extraterrestrials were involved in the great extinctions that had happened millions of years ago.
response: "The Sixth Extinction" is the first episode of the seventh season of the science fiction television series The X-Files. It was first shown on the Fox network on November 7, 1999, in the United States. "The Sixth Extinction" helped to explore new aspects of the series' overarching mythology. The episode was written by Chris Carter and directed by Kim Manners. "The Sixth Extinction" earned a Nielsen household rating of 10.6, being watched by 17.82 million people in its initial broadcast. The episode received mixed to positive reviews from critics.