 The book is a "tour de force" for de Camp, bringing together features of several of the types of fiction he specialized in, including his time travel stories, historical novels, and trademark "domestic science fiction", in which ordinary people encounter the extraordinary—though as it turns out no time travel is involved, it is not a historical novel, and the "ordinary" people live in the twenty-seventh century.Two of de Camp's friends and colleagues, science fiction writers Robert A. Heinlein and Isaac Asimov, with whom he had worked on military research during World War II, were involved in the book in different ways.It features a laudatory introduction by Heinlein and is dedicated to Asimov, whom de Camp stated "helped to push this one over the hump."