PLAYED BY STEVEN WILLAMS
Who is the mysterious and dangerous man who alternately warns and informs Fox Mulder? Is he stringing Mulder along in a complex and devious campaign of disinformation, or is he an ally in the search for the truth? He has more than once admitted that he is afraid of getting killed like his predecessor, Deep Throat, and will not risk his neck for Mulder. He went head-to-head with Assistant Director Skinner after he refused Scully's request for information on Mulder's whereabouts in ‘End Game’. In ‘Soft Light’ he took an even more active role, stepping out of the shadows to intervene directly in Scully and Mulder's case, spiriting away a key figure under Mulder's very nose. Angrily, Mulder told Mr. X he wanted nothing more to do with the man, and Mr. X warned him, ‘You're choosing a dangerous time to go it alone.’ Just whose side is he on? In The X-Files, that answer will always be equivocal. X was killed in ‘Herrenvolk’ but he left Mulder cryptic directions to a new source of information (Marita Covarrubias).