The Lost Years of Merlin is almost entirely Emrys's—the young Merlin's—story. Like most classic quest fantasies, it encompasses two interwoven major themes: good versus evil, and personal growth and self-discovery as the protagonist seeks his goal.

For Emrys, his own goal—to learn who he is and where he is from—comes much earlier. As the book opens, he awakens upon a strange seacoast with a terrible headache and no memory of his past life. Although a woman castaway on the same shore takes him in and insists she is his mother, Emrys does not believe her. She will not reveal much about her own, or his, past. She does teach him herb lore, and tells him marvelous stories about the gods and heroes of many different pantheons. But she refuses to talk about his father, saying Emrys...