When Franny and her older sister Valentine are summoned by their Aunt Theodora from foggy San Francisco to sunny New York City for one summer, they are taken to old-world locales like Bemelmans Bar, the Plaza, and the Sherry Netherland by their chaperone, Clover, Aunt Theodora's protege. As they discover New York City going shopping and learning about the simple elegance of a cucumber sandwich, they also begin to unearth secrets and answers about Aunt Theo's glamorous and romantic past, and they have a few romantic adventures of their own.