Given a second series , Doctor Who kicks off with a sci-fi staple — the heroes are shrunk to about an inch tall. All the usual fun and frolics with perfectly normal household objects becoming perilous deathtraps are there, but they also uncover a plot by a ruthless businessman Forester to launch a new insecticide, DN6, despite it being harmful to other life. A civil servant investigates, but is murdered by the businessman (told you he was ruthless). The Irwin Allen series Land of the Giants bears a remarkable similarity.