Discussions of Bronze Age Troy and the ancient Sudanese civilization of Kush counter romantic speculations with a resume of what is known of them from historical sources and archaeological investigations.

In contrast, the section on King Arthur, of whom little factual information has been established, puts to rest unverified notions regarding him by tracing the development and elaboration of his legend down through the ages.

Chapters in the second category include discussions of memories of previous lives supposedly recovered via hypnosis, the Kabbalah, lives of famous charlatans claiming to have been magicians, such as Cagliostro and Aleister Crowley, the hoax perpetrated by Léo Taxil and others that purported to expose Freemasonry as devil worship, theosophist C. W. Leadbeater, the development of occultist cultism around Mount Shasta in Northern California (demonstrated to have a literary basis), and the origins of the mystic trance, with rational explanations for the visions experienced.

This part of the book also includes reviews of Immanuel Velikovsky's Worlds in Collision and Erich von Däniken's Chariots of the Gods?, both of which de Camp discounts.

"[6] Michael Schuyler, writing for Library Journal, took a more neutral stance, judging only that "[m]ost of these mysteries have been well documented elsewhere, and De Camp [sic] presents no revelations.

[2] More recently, an exhaustive review from 2007 sums up the book as "a very pleasant and readable collection of essays, an excellent and classical example of skeptical writing and debunkery of various kinds of pseudoscientific and paranormal nonsense."