Rosa, belle of the Italian colony, was still fancy free when the young author came to live under her father's roof. He was totally unlike any man she had known, too deeply absorbed in his work to notice that the Italian girl was dying of love for him. Her faithful suitor, Pasquale, and her parents knew what was troubling her but the author did not discover it for a long time. Then he went away, promising to return. But he never came back. Roaming the streets with Pasquale, who played the concertina while she sang, Rosa attracted the attention of an impresario with her beautiful voice. A stage career opened before her. In a few years she was famous. Then the author, called upon to write an opera, met her again in the manager's office. He did not at first recognize, in this radiant creature, Rosa of the East Side, but then he fell victim to her charms. Pasquale, insanely jealous, attacked the author with a knife, but was disarmed by Rosa. When the author asked her to marry him, Rosa had her revenge. "You did not come back to Rosa," she said, "but you are willing to marry the famous prima donna! Is it not so?" And from him, humiliated, she turned to the faithful Pasquale, whose love had remained unchanged by her success.