A cult of sainthood has developed around Calabria's Giacomo Nerone, a mysterious character during the final years of World War II. Monsignor Blaise Meredith, who suffers a terminal illness, is dispatched from the Vatican as a canonical inquisitor known as the "Devil's Advocate" to investigate the presumed holiness. He will find three persons who can help him unlock the case. Each one possesses a vital piece of the puzzle that surrounds the enigmatic life and suspicious death of Nerone. Meredith needs to resolve the mystery, but also find meaning to his own life.