Edgar Wallace 
Fourth Plague [PDF ebook] 

On the Terzo de Citta stands the Palazzo Festini in gloomy, dilapidated magnificence. Here in penurian grandeur dwell the Festinis, a family not afraid to resurrect feuds first begun in the Middle Ages. This is a tale of the Red-Hand, a criminal organisation that makes Count Festini, its secret head, the most dangerous man in Europe. But for his hated eldest son, the Red-Hand’s plans for the downfall of the country may succeed…