A prelude, using Madame Tussaud waxworks and shots of smoke stacks, represents the Victorian age as the era of gas.

Commentator Alistair Cooke explains scientific progress in the postwar years, coinciding with the rise of electricity. A sequence demonstrates how inefficient coal is in industrial and domestic use, with two thirds of its value wasted. A Kentish miner, voiced in exaggerated middle class tones, has to wait two hours for a coal-heated bath. A voice comments on the apparent stupidity of this in a supposed 'age of science.' Cooke explains to the questioner how coal can be used to manufacture gas. Three white-coated, bowler-hatted 'scientists', in operatic voices sing about the disadvantages of coal and offer to 'turn it into clean, flexible, automatic heat for you'.

An animated diagram, followed by a gasworks tour, explains the production of town gas, coke and by-products. The voice demands to know how this affects ordinary people. Use of gas for cooking at a Lyons Corner House, restaurant, and department store is shown. Gas heating and air conditioning are exemplified by their use in a cinema. An interlocutor shown on screen asks how gas can improve smoke problems in industrial areas. Cooke explains its use in industry - in steel works, as a precision energy source in manufacture, and in heating and typesetting at the Daily Telegraph.

Another interlocutor asks about life for the working man and his wife in slum areas. Cooke insists that such people are benefiting too. A 'working-class' woman in a gas-equipped kitchen and Mrs Bumble, a cook general, enthuse about the new technology, while another woman worries what it will cost. Cooke asserts that most subsidised housing since the war has been equipped with gas. A child hymns life in the new flats. Over shots of the gas industry's Kensal House flats, the voice suggests that electricity might do all this better than gas. Cooke cites New Jersey, where many consumers choose gas for heat and electricity for light, and Switzerland (in a joke sequence in which the same shots are run twice, voiced in French, then in English): despite their abundance of hydroelectric power, the Swiss are importing coal to make gas. Over shots of people knitting, doing jigsaws and tending gardens, Cooke concludes by suggesting that leisure time is more relaxed now that clean and easy gas is a part of everyday life.