Uncle Jack (Paul Jones) is an eccentric cross between an eco-warrior and a mad scientist. His activities embroil him and members of his family (usually nieces and nephews) in various unlikely adventures and constant danger. Jack has a regular nemesis, the evil Vixen (Fenella Fielding), whose plans invariably spell disaster for the ecology of the planet.
'Uncle Jack and The Dark Side of The Moon' is the third series of the Uncle Jack adventures, the others being: series 1: 'Uncle Jack And Operation Green', series 2: 'Uncle Jack And The Loch Noch Monster' and series 4: 'Uncle Jack And Cleopatra's Mummy'.
Each series (evident from the titles) had a different story. 'Uncle Jack and The Dark Side of The Moon' involved the Vixen trying to control the world's weather.