The X-Files was a popular television show during the 1990s and early 2000s, which primarily followed the investigations of two FBI agents, Fox Mulder and Dana Scully, who were sometimes helped by a group of conspiracy theorists known as The Lone Gunmen.
The X-Files based the plots of many of its episodes around urban legends and conspiracy theories, and had a framing plot which postulated a plot for alien invasion overseen by elements of the U.S. government, led by an individual known only as the Cigarette Smoking Man and an even more mysterious international “Syndicate”. Many viewers still believe that the X Files stories are based on real cases.