Odd film this - a sort of propaganda (workings of the crews on barrage balloons), with a sort of poor man's Gert and Daisy comedy stage act in the form of Ethel Revnell (6' 1") and Gracie West (4' 11") known as "The Long and the Short Of It", and presumably they made a living on the stage, as this was one of only 3 films they made.
Gooning their way through a few comedy songs and, as is usually the case, fall upon and get arrested some fifth columnists, more by accident than design.
Add to the mix the unfunny comedy actor Ronald Shiner and the crooner Donald Peers, and you have a cringe worthy hour of entertainment and "laughs"