On the eve of an announcement he claims will send shockwaves through the world's Christian community, a distinguished professor of religious studies is mysteriously found dead. When an ambitious colleague, Nolan Lemay, discovers that the announcement involved disclosure of a first century letter claiming the disciple Thomas to have been the literal twin of Jesus of Nazareth, Lemay attempts to acquire the manuscript and finds his own life in danger. Three young women, trained from their youth to safeguard the secrets of an ancient text held by a small sect of St. Thomas Christians in southern India, track Lemay across Southeast Asia as he first attempts to make public the letter's startling contents, then flees to escape the zealous pursuit if the Guardians of the Second Son.