Season 7 Episode 18 (March 7, 2001): Human Error

Season 4 Episode 26 (May 20, 1998): Hope and Fear

Season 4 Episode 11 (November 26, 1997): Concerning Flight

Season 6 Episode 4 (October 13, 1999): Tinker, Tenor, Doctor, Spy

Season 4 Episode 3 (September 17, 1997): Day of Honor

Season 4 Episode 2 (September 10, 1997): The Gift