High Quality Content by WIKIPEDIA articles! The ninth season of the American science fiction television series The X-Files commenced airing in the United States on November 11, 2001, concluded on May 19, 2002, and consists of twenty episodes. Season nine takes place after Fox Mulder`s leave after the events of the eight season finale, "Existence". Mulder is in hiding during the whole season, with the exception of the series finale, "The Truth".