When German-born Katharina Brandt immigrates from Amsterdam in 1938, her dearest wish is to become a real American girl. From now on, her name is Katherine Small, and she adopts the nickname Sparky to try to seem even more American. But before she can realize her dream, she'll have to learn the ins and outs of her unusual new neighborhood and group of friends in Atlantic City.
Sparky is taken under the wing of Cinnimin Filliard, the youngest child of the man who helped the Brandts immigrate. Cinni teaches her a thing or two about American life and their strange neighborhood. Sparky wants to believe Cinni is steering her right, but Cinni has some conflicting attitudes. Cinni is nice and intelligent, but she often cops a superior attitude just because she was voted Most Popular Girl. Particularly to neighbor Violet, whom Cinni is convinced is after her title.
Sparky will do almost anything to fit in, except compromise her Judaism. She longs to be Sparky to her friends while remaining Kätchen to her family and staying true to her values. But along the way, Cinni, who tries to tempt her into wearing shorter skirts and eating non-kosher food, slowly begins realizing there's more than one acceptable way to be a real American.
Will she ever be able to pull off being Sparky to her friends while remaining Kätchen to her family and staying true to her values? And just why was she nicknamed Sparky?