 Nutter, Morgan and Wong had all previously collaborated on both "Millennium" sister show "The X-Files", and the Morgan and Wong-created series "".Guest star Hiro Kanagawa, who portrays FBI special agent Takahashi, has appeared several times in "Millennium" sister show "The X-Files", in the second and fourth seasons; as well as in "The X-Files" spin-off series "The Lone Gunmen".Kanagawa would also make several more appearances on "Millennium", acting in unrelated roles in the episodes "The Time Is Now", "Human Essence", and "Bardo Thodol".