 After receiving approval from series creator Chris Carter, Goodwin spent approximately six weeks writing the final episode.The episode explores the past of The Smoking Man, the series' chief antagonist.William B. Davis, the actor who played the character, later noted, "As the story developed, we developed a relationship between Cigarette-Smoking Man and Mulder's apparent father, and Cigarette-Smoking Man and Mulder's mother; then we started backfilling with an historical connection."