- Creator's Pest: John Nathan-Turner hated K9, so Part One opens with him being short-circuited after going in the sea and playing no part in the rest of the story. He'd be gone by the end of the season.
- Dueling Shows: The serial suffered in the ratings against ITV's import Buck Rogers in the 25th Century.
- Real-Life Relative: The baby Pangol was played by Alys Dyer, whose mother was production unit manager Angela Smith.
- Troubled Production: Production of the serial was extremely challenging. Tom Baker and Lalla Ward's tumultuous off-screen relationship was at a nadir, causing the mood on set to be distinctly chilly. Director Lovett Bickford's management of the shoot caused it to go so badly over budget that John Nathan-Turner was severely reprimanded by his superiors. Bickford would never work on the series again.
- Working Title: The Argolins and Avalon.
- You Look Familiar: Laurence Payne had previously played Johnny Ringo.
Trivia / Doctor Who S18 E1 "The Leisure Hive"