Professor Hoyle's time travel science fiction adventure is a modern relative of The Time Machine by H.G. Wells.

Solar beams plays havoc with terrestrial time: England is in the '60's, but WWI is still raging in western Europe, Greece is in the golden age of Pericles, while the United States is some thousands of years in the future; and Russia and Asia are reduced to a glass-like plain, fused by the burnt-out sun of a far distant future.

The central themes are time and the meaning of consciousness. The heroes are a pianist-composer and his scientist friend. The dramatic highpoint of the book is a magnificent, almost idyllic section on the life and music of the future, in which one can almost hear the compositions of two rivals as they compete in improvisations.