Episode 11 - The Gift
Doggett comes upon an old case that Mulder kept secret from Scully.
Aired: February 4, 2001
Writer: Frank Spotnitz
Director: Kim Manners
Trivia: The scene with the Lone Gunmen talking via Internet videophone to Doggett and Skinner was actually shot on the set of the spinoff series, with Bryan Spicer directing.