It marks the final appearance of Sophie Aldred as Ace in a regular television serial; although she would reappear for the special 1993 Children in Need special Dimensions in Time. It was also the last time that Anthony Ainley appeared as in a regular televised story; he appeared one more time in the video game Destiny of the Doctors. Ainley's final portrayal of the Master in the original series is considerably different - subtle and darker than the often bombastic and forceful impression he had been told to deliver since Logopolis; Ainley had always intended to portray the Master with this calmer characterization.