The episode features Hattie Hayridge's last appearance in the series. According the Series V DVD documentary "Heavy Science", the writers had simply run out of ideas for Holly, with Doug Naylor expressing guilt over the fact Hayridge's role in the show was often little more than a few lines. Holly would return to the series at the very end of Series VII and become a regular for Series VIII, but would be played by the character's original actor, Norman Lovett. Nevertheless, Hayridge would stay involved with the fandom and also participate in interviews and commentaries for the DVD releases of her seasons.
Timothy Spall, who has a guest appearance as Andy, was extremely nervous during shooting, because he had never performed in front of a television studio audience before. It took him many takes to say his lines correctly.
Several model shots of the Despair Squid were filmed but it was decided that they didn't work well. Instead a superimposed shadow was used to illustrate the squid closing in on Starbug.
Rob Grant has described this episode as one of his favourites: "that was a show I was sorta in the director's chair for and personally it's a gobsmackingly good show in terms of RD shows."
Lenny von Dohlen: The cop in the alternate reality, better known for playing Harold Smith on Twin Peaks.