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) to Doomsday" (1982), and a message to the same effect is related from the Tenth Doctor in "Utopia" (2007). In talking with Harry in "Robot" (1974–1975) the Doctor states "You may be "a" doctor, but I'm "the" Doctor. The definite article, you might say." In "The Ark in Space" (1975), aired later that year, the Doctor states that his doctorate is only honorary; the Tenth Doctor, however, considers the name to be his legitimate academic rank in "The Waters of Mars" (2009), describing his "name, rank and intention" as "The Doctor; doctor; fun." In an interview with "The Age" in