The Mysterious Mr. Miller by William Le Queux

I dined at a small table alone in the big crowded _table-d'hote_ room of the hotel. About me were some of the most exclusive set in Italy, well-dressed men and women, Roman princes, marquises and counts, with a fair sprinkling of the Hebrew fraternity. At the table next mine sat a young prince of great wealth together with the fair American girl to whom he was engaged to be married, and the young lady's mother. The prince and his fiancee were speaking Italian, and the old lady from Idaho City, understanding no other language but her own, seemed to be having anything but an amusing time.

All this, however, interested me but little. I was reflecting upon the events of that afternoon, trying to devise some means by which to solve the enigma that was now driving me to desperation.