Between the two world wars, on a hike in the English countryside, Professor John Hill takes refuge from a violent storm in a cave. There he nearly loses his life, but he also makes an astonishing discovery - an ancient manuscript housed in a cunningly crafted metal box. Though a philologist by profession, Hill cannot identify the language used in the manuscript and the time period in which it was made, but he knows enough to make an educated guess - that the book and its case are the fruits of a long-lost, but advanced civilization.

The translation of the manuscript and the search for its origins become a life-long quest for Hill. As he uncovers an epic that both enchants and inspires him, he tracks down scholars from Oxford to Paris who can give him clues. Along the way, he meets several intriguing characters, including a man keenly interested in obtaining artifacts from a long-lost civilization that he believes was the creation of a superior race, and will help him fulfill his ambition to rule other men. Concluding that Hill must have found something that may help him in this quest, but knowing not what it is and where it is hidden, he has Hill, his friends at Oxford, and his family shadowed and threatened until finally he and Hill face off in a final, climactic confrontation.

A story that features a giant pirate and slaver, a human chameleon on a perilous metaphysical journey, a mysterious hermit, and creatures both deadly and beautiful, this is a novel that explores the consequences of the predominant ideas of the 20th Century.