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) and fourth Doctors with whom she had previously travelled. In "Time Crash", the Tenth Doctor remembers and reproduces what he saw himself do when he was the Fifth Doctor, a fact that seems to surprise the Fifth Doctor himself. Russell T Davies has expressed a dislike for stories in which multiple incarnations of the Doctor meet, stating that he believes they focus more on the actors than on the story itself. In 2007, David Tennant showed enthusiasm for the idea of a multi-Doctor story, but expressed doubts about the practicality of episodes involving multiple previous Doctors, given that three of