 The Doctor and Mel visits Paradise Towers, a apartment complex in the 21st century. Only to find the apartment building has become rat-infested and ruined and Paradise Towers is inhabited by The Rezzies, elderly women who are cannibals, The Kangs, gangs of teenage girls, Pex, a cowardly warrior who claims he is the local hero, and The Caretakers led by the Chief Caretaker whose job is to keep the apartment complex in order. But the Doctor and Mel find everyone in Paradise Towers are being killed off one-by-one by the robotic cleaners, only to discover the culprit is Kroagnon, the building s award-winning architect who plots to rid Paradise Towers of all those who live within it.