Naples, 1750. In the dead of night, three men with swords burst into the bed chamber of the Marquis de Montferrat. Their leader, Raimundo di Sangro – the Prince of San Severo – accuses him of being an imposter, and demands to know a secret he believes the marquis harbors. The false marquis resists and manages to escape, leaving behind a burning palazzo and a raging prince now obsessed with finding his quarry – and his secret – at any cost.