Inspired by a real manuscript in the rare book library at Yale University--and centering on the insights of an autistic child--this fast-moving mystery brings together the fields of cryptology, church history, and clinical psychology. As the tale begins, Father Ronald McCallum is a Vatican guard secretly placed to watch over a 400-year-old document written in a code that has never been deciphered. He is startled one day when a boy visiting the library appears to read from the manuscript's pages. After some consultation, the Vatican decides to send in an expert--Father Benicio Valori, a priest and clinical psychologist--to verify the boy's surprising skills. These efforts are thwarted, however, when the manuscript is stolen by mysterious agents hoping to prevent its secrets from being exposed. Fearing for the child's life, Father Valori takes young Matthew and flees to Canada to consult his trusted friend, Dr. Jake Tunnel, a fellow psychologist; and soon the two men begin to unveil the biblical origins of the stolen manuscript--and to develop a theory of their own about why this autistic child can decode it so successfully.