The series moved filming locations from Vancouver to Los Angeles beginning with this episode.
The second most watched episode of Season 6.
The part of Sandy, the Syndicate scientist who unwittingly incubates an alien inside him, was played by casting director Rick Millikan.
The "previously on..." prologue contains scenes from both the previous episode The End (1998) and the movie The X Files (1998). The movie takes place between the end of season 5 and the beginning of season 6.