A tale of two kids in the city shows Rose conquering her fears and making a new friend. Of all the noises New York City can produce, the ones that frighten Rose (who looks about four) are those she hears over her head, made by her upstairs neighbor. Even though her mother tells her ``it's just Sebastian,'' Rose asks to meet the boy, and a mother-summit results in a tea party where the riled-up boy demonstrates his lung power up close. ``ARRGH ARRGH ARRGH,'' he likes to scream. Rose laughs and they show each other their toys; that night in bed, Rose shakes up Sebastian with some screeching of her own. According to the illustration, Sebastian takes this surprise in stride. Accomplished, stylized drawings help put the lighthearted story across, and Zarin offers not only a glimpse of apartment life, but establishes Rose as a captivating heroine who wants to overcome her fears, and does. (Picture book. 4-8)