Antone Tojetti and his pretty daughter, Maria, are street musicians in Venice. John Strom, an American millionaire, makes love to Maria, and finally persuades her to leave for America with him. Her father sees them just as they are leaving, but she will not return to him. Two years later, Maria, abandoned by John, returns to her father, who has now become a guide in the mountains. She dies and Antone vows vengeance. Some time after this, John Strom, now married, is touring Europe and he and his party seek a guide to visit Vesuvius. Antone takes the position. John not recognizing in him the father of Maria.