The protagonist of the novella is a well-educated man, a contemporary of the author, who suffers from a split personality. Since childhood, he has experienced dreams in which he is transported to prehistoric times, among primitive people who have not yet learned to speak and still retain their hair. Each night, he dreams a continuation of the previous dream—nature, hunting, and interactions with other half-human, half-ape tribes. These visions terrify him, and only as he matures is he able to reconstruct the life of his alter ego from the fragments of these dreams. The book we present to readers contains the unadapted text of the novella, supplemented with commentary and a glossary.