The exploits of FBI Special Agents Fox Mulder and Dana Scully who investigate X-Files: marginalized, unsolved cases involving paranormal phenomena. Mulder believes in the existence of aliens and the paranormal while Scully, a skeptic, is assigned to make scientific analyses of Mulder's discoveries that debunk Mulder's work and thus return him to mainstream cases.
Mulder's dreams help him in finding the body of a little girl which reopens one of his old cases in the Violent Crimes Unit. This leads him to believe that the killer he captured had more victims and that Mulder's sister Samantha may have been one of them.