to be added
- Rotar City is the capital city of Tarron.
- This story is told almost completely through in-story news items.
- The Doctor bristles at being called "Doc". (TV: The Time Meddler et al.)
- Dodo relates having witnessed the destruction of the Earth by solar flares and its survivors travelling to Refusis. (TV: The Ark)
- The Doctor reacts to being called "Grandfather", implying that he is reminded of Susan. (TV: The Dalek Invasion of Earth)