In the heavens, three demigods debate the usefulness of the inhabitants of the planet Earth. As an experiment, one of them, Player, decides to bestow a limited amount of power upon one of these 'creatures' in order to observe their potential. Player's choice, lowly draper's assistant George McWhirter Fotheringay, unknowingly receives this power as he is about to enter his local public house.

During a pub conversation on the possibility of miracles, Fotheringay inadvertently commands a ceiling lamp to turn upside down; to everyone's amazement, it does precisely that. However, he is ejected from the pub when he is unable to keep the lamp in its new position and it falls to the floor.

At the haberdashers where he works, following an evening practicing his new powers in his lodgings, Fotheringay demonstrates his abilities to workmate Maggie Hooper by curing her sprained arm and conjuring up a bouquet of violets. Declaring him a hero, she wonders at all the good he could do. Fellow worker Ada Price, on whom Fotheringay has a crush, imagines how rich and powerful he could become, but Maggie advises caution and warns him not to use his powers for selfish ends.

Meeting Ada in the street later that evening, Fotheringay attempts to will her to love him using his powers, but his failure to do so makes him realise that he cannot influence a person's will.

Fotheringay's employer, Major Grigsby, in concert with his banker Bamfylde, attempts to persuade him to limit the use of his powers to the service of the business in exchange for a pay rise and his name added to that of the shop. In contrast, Baptist Minister Silas Maydig tells him how his miracles provide hope for the human race, bringing forth a 'golden age' of peace and plenty. He should ignore the temptations of Grigsby and Bamfylde as there will be no need for business and banking in this new world.

Local Chairman of the Bench, Colonel Winstanley, on learning of the spate of miracles in the town, concludes that Fotheringay must have been responsible for changing his collection of weapons into agricultural tools, something Maydig had urged him to do. Confronting Fotheringay, the colonel, an avowed opponent of progress, learns to his horror how this 'common man' intends to change the world, all of which goes against his own desire to maintain the status quo. The following day, in an attempt to avert any possible change, the colonel attempts, but fails, to shoot Fotheringay while he is walking with Maydig.

Denouncing everyone for trying to use him, Fotheringay declares that he is going to change the world to how he wants it to be - and now. Changing the colonel's house into a grand palace, he summons all of the world's leading bankers, businessmen, politicians and military leaders to tell them that they need to run the world better. They have done nothing for the common man in the past, but now their power has come to a 'common vulgar fellow' like him and, knowing that he cannot affect their collective will, he tells them that they themselves have to create a better world now or he will 'wipe them out'.

Fotheringay stops the world from spinning so as to provide ample time for the 'leaders' to create a new world, but the consequent absence of gravity results in everything on Earth flying off into space. As he whirls around above the planet, Fotheringay wishes himself back to that night when he was about to enter the pub, and denies himself the power to work miracles.

Observing these events, two of the demigods denounce humans for their egotism and observe that they will never progress. Player, however, believes there is hope for these creatures, and decides instead to give them power in smaller portions over time, with enough accompanying thought and wisdom to effect a different result.

In the pub, Fotheringay, during that same conversation on miracles, tries to move the ceiling lamp as before, but this time it remains stationary. He wistfully ruminates on how he will now never be able to change things in this world.