Trout’s book presents an interesting hypothesis about the origins of myth and storytelling. The author conceives the development of storytelling in the very ancient past as a mechanism of early human beings to cope with the fear of predators. The purpose of the book is to “explain in detail how and why the animal predators of the Pleistocene got inside our heads and our stories” (25). Trout reminds his readers right at the beginning that, before human beings became the most efficient predators on the planet, they were the prey for about two million years, and until only about ten thousand years ago. For most of this time, humans had only stones and sticks to ward off predators.

The book is divided into ten chapters. The first introductory chapter, in which the purpose and method of the book are explained, is very short. Trout sets out to clarify why we are still so fascinated with stories about predators, real or fictitious. His purpose is also to discover the role that predators played in the evolution of storytelling itself.

The second chapter, "Bringers of Death", presents a survey of the predators which our ancestors encountered. Besides those still living and devouring humans in our own times, such as tigers, lions, wolves, bears, crocodiles, sharks, and snakes, the Pleistocene had a variety of fierce and dangerous animals to fear. Not only were those animals much larger than the current ones, but human beings were also not yet confident hunters, although not completely defenseless.