It was originally intended that the Doctor's previous travelling companions, Ian and Barbara,
were to appear in cameo roles, walking across the scene set on Wimbledon Common in 1966.
Unfortunately, this was not possible, and the scene had to be rewritten.
After transmission of the final episode, Jackie Lane was told by the production team to drop a Cockney accent,
and speak in a manner that was more representative of the BBC.
So the viewers therefore would detect a noticeable change in Dodo's accent at the start of the next story, The Ark.
As for me, for some of you may not know that I was to appear once more in Doctor Who, 15 years later,
as Birok, the time-sensitive tarot in the 1981 Tom Baker story entitled Warrior's Gate.
Warrior's Gate