Christmas Rushed: The original 2016 animated version was rushed so it could be released to mark the 50th anniversary of the serial's original broadcast, meaning the production team had half the time they originally expected to make it in. It was revised for a 2020 Special Edition re-release, described by the original director as "twenty times better".
Limited Special Collector's Ultimate Edition: In the UK, the black and white animated version was given a regular DVD release (matching the rest of the range) in November 2016, followed by a DVD/Blu-ray Collector's Edition steelbook with both black and white and colour versions in February 2017. Notably, the steelbook is the only way to get the colour version on DVD, and the only way to get either version on Blu-ray. The US instead received a DVD with both versions, but no Blu-ray release at all. There was also a Special Edition in 2020, which improved the animation and added some new DVD Bonus Content.
Meaningful Release Date: The 2016 animated version's original release coincided with the 50th anniversary of the story's original broadcast, and the 2020 Special Edition with Patrick Troughton's centenary (as well as being released in the year the story actually takes place in).
Missing Episode: All six episodes remain missing. Suffice to say that this may be one of the most sought-after missing stories.
Uncredited Role: David Whitaker is the credited writer, but the script was largely re-written by an uncredited Dennis Spooner, who was hired as an anonymous ghostwriter when Whitaker was unable to.
David Whittaker’s initial scripts revealed the Doctor’s actual age, as well as that this wasn’t his first reincarnation (then still called “revival”).
Working Title: The Destiny of Doctor Who and Servants of the Masters.
You Look Familiar: Edward Kelsey (Resno) had previously appeared in "The Romans", becoming the first actor to play guest roles opposite more than one Doctor.
Assorted Trivia:
A 1993 cassette release of the audio of "The Power of the Daleks" has Tom Baker doing narration in-character as the Fourth Doctor, as if the Fourth Doctor was recounting a memory of his.
This was the only Troughton-era story not to feature Frazer Hines as Jamie McCrimmon. Jamie would be introduced in the next story and remain for the rest of Troughton's run.
