Paradise Towers two elderly residents ("rezzies") live. Tilda and Tabby explain that all the able-bodied men left the Towers to fight a war, leaving behind only children and the elderly. The only other man still loose in the Towers is Pex, a would-be hero, who appoints himself Mel's guardian. At the Caretaker control centre, the Doctor meets the Chief Caretaker, who greets him as the Great Architect, designer of Paradise Towers, and then promptly calls for him to be killed The Doctor cites an imaginary rule from the Caretakers' manual, confusing them enough to make his escape. Mel and Pex meanwhile have
The Doctor (Doctor Who) footage. Tom Baker did reappear, but as "the Curator", an ambiguously different character who he was not credited for playing. A voice actor, John Guilor, recorded a line of audio impersonating the First Doctor, for which he was credited as "Voice Over Artist". In other multi-Doctor stories, the multiple actors are all credited as "The Doctor", the exception being "The Three Doctors" (1972–73), which credited William Hartnell, Patrick Troughton and Jon Pertwee as "Doctor Who" as the 1972 serial preceded the practice of crediting the character as "The Doctor". In "Human Nature" (2007), the plot involves the Tenth Doctor altering