"The X-Files" follows the careers and personal lives of FBI Special Agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson). Mulder is a talented profiler and strong believer in the supernatural. He is also adamant about the existence of intelligent extraterrestrial life and its presence on Earth. This set of beliefs earns him the nickname "Spooky Mulder" and an assignment to a little-known department that deals with unsolved cases, known as the X-Files. His belief in the paranormal springs from the claimed abduction of his sister Samantha Mulder by extraterrestrials when Mulder was 12. Her abduction drives Mulder throughout most of the series. Because of this, as well as more nebulous desires for vindication and the revelation of truths kept hidden by human authorities, Mulder struggles to maintain objectivity in his investigations.