Meanwhile is divided into two books: "The Utopographer in the Garden" and "Advent".

In the first book, Cynthia and Philip Rylands, a wealthy British couple, are entertaining guests at Casa Terragena, an Italian villa with a famous garden on the Italian Riviera. Among the party are a prominent author, "the great Mr. Sempak," an American aesthete, Mr. Plantagenet-Buchan, the beautiful, vivacious Lady Catherine, Col. and Mrs. Bullace, Lady Grieswold, and a number of others. At dinner, Sempak, a brilliant talker with ideas similar to Wells's, expounds the idea that a "Great Age" is certain to come, and that contemporaries are obliged in the present to live, as it were, "meanwhile": "Since nothing was in order, nothing was completely right. We lived provisionally. There was no just measure of economic worth; we had to live unjustly .... We were justified in taking life as we found it; in return if we had ease and freedom we ought to do all that we could to increase knowledge and bring the great days of a common world-order nearer, a universal justice, the real civilisation, the consummating life, the days that would justify the Martyrdom of Man."