The title refers to the 'balloon going up', a popular euphemism for an anticipated German invasion of Britain during the Second World War.
balloon | Balloon (aircraft) | Five Weeks in a Balloon | The Red Balloon | Let the Balloon Go | Barrage balloon | United States Army/"Union Army" Balloon Corps | Union Army Balloon Corps | The Gilded Balloon | The balloon ''The Skywhale | The Balloon-Hoax | Speech balloon | speech balloon | S. A. Andrée's ill-fated arctic balloon expedition of 1897 | S. A. Andrée's Arctic Balloon Expedition of 1897 | Piccinini's balloon "The Skywhale | List of American Balloon Squadrons | Five Weeks in a Balloon (film) | Columbia Scientific Balloon Facility | Bristol International Balloon Fiesta | barrage balloon | Balloon Kid | balloon (aircraft) | A '''TA''' balloon at Cambridge Bay | 2012 Carterton hot air balloon crash |