Fox William Mulder is a fictional FBI agent and one of the two protagonists of the Fox science fiction-supernatural television series The X-Files, played by David Duchovny. Mulder's peers dismiss his many theories on extraterrestrial or paranormal activity as conspiracist however his skeptical but supportive partner Dana Scully often finds them to be unexpectedly correct. He and Scully work in the X-Files office, concerned with unsolved FBI cases that are often revealed to be supernatural or extraterrestrial in nature. Mulder was a main character for the first seven seasons, but was limited to a recurring character for the following two seasons. He returns as a main character for the tenth and eleventh seasons. Mulder made his first appearance in the first season pilot episode, broadcast in 1993. Mulder believes in extraterrestrial unidentified flying objects (UFOs) and a government conspiracy to hide or deny the truth of their existence. Mulder considers the X-Files and the truth behind the supposed conspiracy so important that he has made them the main focus of his life.