In these short texts is depicted an encounter with a "happy, active-looking" old man: the protagonist and author of the first-person narrative, writing the story of his life immediately before and after "the Change".

Book I, recounts that William ("Willie") Leadford, "third in the office staff of Rawdon's pot-bank [a place where pottery is made] in Clayton,"[3] quits his job just as an economic recession caused by American dumping hits industrial Britain, and is unable to find another position.

He returns to being a student and his emotional life is dominated by his attachment to Nettie Stuart, "the daughter of the head gardener of the rich Mr. Verrall's widow",[3] of a village called Checkshill Towers.

As this plot matures, a comet with an "unprecedented band in the green" in its spectroscopy looms gradually larger in the sky, eventually becoming brighter than the Moon.

Book II opens with Leadford's awakening, in which he is acutely aware of the beauty in the world, he can think much more clearly, and his attitude toward others is one of generous fellow-feeling.

He lives in lodgings with his timid, work-worn, but loving mother, widowed by a train accident, who believes in "a quaint old-fashioned narrow faith.

Various organisations dedicated to preserving public morals, including the YWCA, Salvation Army and 'Anti-Vice and White Slavery' campaigners, spoke out against the book, as did several influential reviewers: 'socialistic men's wives, we gather,’ said the Times Literary Supplement, 'are, no less than their goods, to be held in common.

On 18 October 1906, Beatrice Webb wrote in her diary: "In the Days of the Comet ends with a glowing anticipation of promiscuity in sexual relationships ... [but] Wells is, I believe, merely gambling with the idea of free love—throwing it out to see what sort of reception it gets—without responsibility for its effect on the character of the hearers.