Strange news arrives in Florence, on the banks of the river Arno, a galley has been found, the entire crew dead. Dante Alighieri, Prior to the City, suspects poison. The only clue is a damaged mechanical device, possibly of Arabic origin. Frederick II, Holy Roman Emperor, known for his obsession with science and medicine, would have been one of the few who could understand such an instrument. At a time when conspiracy theories abound concerning the death of the Emperor, is this a coincidence or something more sinister? Whilst working on his magnum opus the Divine Comedy, Dante returns to the city only to discover the renegade monk, Brindano, stirring up trouble and recruiting Florentines for a new crusade to liberate the Holy Land. In "The Kingdom of Light", Leoni paints an atmospheric medieval Florence, seething with plots and intrigue, and in Dante delivers a credible, intuitive detective and a fascinating man.