Deep inside the Vatican library, a priest discovers the rarest and most valuable art object ever found: the manuscript of "The Divine Comedy," written in Dante's own hand. Via Sicily, the manuscript makes its way from the priest to a mob boss in New York City, where a writer named Nick Tosches is called to authenticate the prize. For this writer, the temptation is too great: he steals the manuscript in a last-chance bid to have it all. As this dark and twisted journey unfolds, so too does a parallel tale: the odyssey of Dante himself, a man trying to weave a poem that contains the sum of the world's wisdom and the very breath of the divine.