FBI Agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) investigate cases involving paranormal phenomena, classified as “X-Files.” Mulder is the “believer,” having faith in the existence of aliens and the paranormal, while Scully is the skeptic and often works to disprove Mulder’s theories. They work under the direction of Assistant Director Walter S. Skinner (Mitch Pileggi). Later in the series, FBI Agents John Doggett (Robert Patrick) and Monica Reyes (Annabeth Gish) are prominently featured.