- Creator Backlash: Terry Nation was unhappy with Douglas Adams' rewrites, particularly the scene where the Doctor taunts the Dalek by suggesting it climb after him, as he believed that pointing out the Daleks' apparent design flaws made them less menacing, and threatened their popularity with the viewing public. This turned out to be his final contribution to the series.
- Creator's Pest: It was long believed Terry Nation hated K9 and didn't want him to overshadow the Daleks, so he wrote him out of the story by giving him laryngitis. While the first part may well be true, the real reason K9 takes a break this week was more mundane see below.
- The Other Darrin:
- David Gooderson replaces Michael Wisher as Davros, as Wisher had a theatrical commitment in Australia. Also a general Man in a Kilt, as Davros has magically become Scottish.
- K9 was voiced by Dalek voice actor Roy Skelton. This was because K9 had contracted laryngitis and all that was needed of him was a croaking sound.
- Prop Recycling:
- One of Romana's alternate bodies is wearing Zilda's costume.
- Of the four Dalek casings used in this story, one was reused from "Planet of the Daleks" and the other three were left over from the 1960s.
- The Davros mask was Michael Wisher's from "Genesis of the Daleks", and was only repaired to fit David Gooderson as there wasn't money in the budget to construct a new mask for Gooderson. Because the mask was too small to fit properly, Davros's mouth is noticeably stiff whenever he talks.
- Parts of the Dalek slaves' costumes were recycled from previous aliens for example, one wears the costume (but not the mask) of a Draconian, another the trousers from an SV robot, another has the head of a humanoid-form Axon, and another is wearing a blue Morestran spacesuit.
- Uncredited Role: The three alternative physical forms of Romana were played by Yvonne Gallagher, Lee Richards and Maggy Armitage respectively, who remained uncredited both on-screen and in Radio Times.
- Urban Legends: Contrary to what is commonly reported, K-9's being sidelined for the story is actually unrelated to John Leeson leaving or Terry Nation's supposed antipathy towards him. David Brierly had been cast several months before the story was filmed, and K-9 wasn't given any dialogue (as with "City of Death") so that they wouldn't have to pay Brierly a full episodes' salary just for a couple of lines.
- What Could Have Been:
- Much of the story originally took place at night, but the budget would not permit this kind of location filming, and so it had to be rewritten for the day.
- In the original script, K-9 was trapped in the TARDIS due to a rockfall, while the Daleks searched for Davros because he can supply information about special circuitry which will help them break the deadlock.
- Written-In Infirmity: K-9's laryngitis is because Terry Nation didn't want him overshadowing the Daleks, and the prop wouldn't work on location filming.
- You Look Familiar: Lalla Ward, after guest-starring as Princess Astra in the previous episode, takes on the role of Romana; the episode spends several minutes climbing out from under the weight of the lampshade. (It doesn't help that Terry Nation turned in his scripts before Romana's re-casting was confirmed; Douglas Adams had to write the new opening scene himself, and the resultant change in tone is jarring.)
Trivia / Doctor Who S17 E1 "Destiny of the Daleks"