Sam Scrope, an American traveling through Italy with a friend, finds himself near Lake Albano with Angelo, a young peasant who possesses an ancient object of great value: an engraved gem, an intaglio. Scrope cunningly succeeds in taking the antique for himself, and soon thereafter meets a young American tourist, Adina Waddington, with whom he falls in love and to whom he offers the topaz. But Angelo, wizened to the true value of the intaglio and offended by the trick he has been subjected to, prepares his vengeance. Told through the eyes of Scrope's traveling companion, this story offers a subtle game of passions, as well as an example of the confrontation between two worlds and two mentalities: the American one and the one from the old continent.