John Shiban pens an episode that brushes up against the mythology episodes as it sees the return of Mulder’s (David Duchovny) ‘ally,’ Senator Matheson (Raymond J. Barry) and the villainous, Krycek (Nicholas Lea). First airing on 17 January, 1999, S.R. 819 sees Skinner (Mitch Pileggi) falling deathly ill after being infected with some strange virus….