The Count's Chauffeur by William le Queux

Last spring Count Bindo again renewed his lease of the furnished villa on the Viale dei Colli, that beautiful drive that winds up behind the Arno from the Porta Romana, in Florence, past San Miniato. It was a fine old place, standing in its own grounds, and was the German Embassy in the days when the Lily City was the Italian capital.

There were reasons for this. Sir Charles Blythe was living at the Grand, and Henderson was at the Hotel de la Ville. A _coup_ was intended at one of the jewellers on the Ponte Vecchio -- a place where it was known that there were a quantity of valuable pearls.