In 15th Century Spain, the Fallen Angel, Leviathan, a Demon Prince of Hell, trades the gravest secret of Creation to save himself from the world's greatest exorcist, Father Salvatore Blackwell de Seville, the Inquisitor. The demon tells the priest how a mortal can kill the devil. Blackwell will risk anything to destroy Lucifer, the enemy of God and Creation. He will pursue the power he needs using the darkest sorcery... ... even if it means the end...