Jill Townsend was sick throughout filming with suspected flu; it turned out to be appendicitis. She insisted on carrying on and having the operation after filming.
This episode was filmed at the same time as Devil's Planet (1977) (November 2nd to the 16th 1976), resulting in the only absence of Martin Landau.
The scene with Tony discussing the neuro-pulsonic jammer with Sam Malcolm was originally scripted with Alan Carter and Malcolm (which would've been more consistent amid the story, but Fred Freiberger valued the character of Tony Verdeschi above Alan Carter).
The final appearance of Yasuko Nagazumi (her first episode since The AB Chrysalis (1976)). Zienia Merton's replacement - Alibe Parsons (as Alibe) - was working on Devil's Planet (1977), which was being shot simultaneously with this episode, so they needed Nagazumi here.
Writer Christopher Penfold reportedly remarked that the only thing he recognized in the finished episode that had been in his original script was the title. Since his basic story remained, he retained the writing credit. Various Season Two writers complained that their works had been "butchered" at the hands of producer/script editor Fred Freiberger.