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) 2003, Tom Baker mentioned that the Doctor is called so because he is "a doctor of time and relative dimension in space". Apart from being called a doctor of the TARDIS, the Doctor has been referred to as a "doctor of time travel." The revived programme establishes that Time Lords invent their own names. In "The Sound of Drums" (2007), the Tenth Doctor remarks to the Master that they both chose their names, with the Master calling him sanctimonious for identifying himself as "the man who makes people better." "The Name of the Doctor" and "The Day of the Doctor"