This was actually the first serial of the season to be filmed. As a result, Lalla Ward's performance and manner of dress as Romana is somewhat different from that seen in the previously broadcast serials, since she was still working out her character at the time.
This was Terry Walsh's final appearance in the series having appeared in various roles since 1966 as well as acting as fight arranger and the stunt double for both Jon Pertwee and Tom Baker.
This was the last serial directed by the series' longest-serving director, Christopher Barry. He was reluctant to return to the series as he had become rather tired of working on it by this stage.
Christopher Barry found Tom Baker very difficult to direct in this serial because Baker had become very domineering and wanted to direct himself.
Lalla Ward disliked this story. She was unhappy that her white costume was an intentional echo of Mary Tamm's original outfit from The Ribos Operation, and also felt that David Fisher had done a poor job of rewriting his scripts for her incarnation of Romana. Graham Williams agreed that, in the future, Ward should have more say in her character's portrayal.