Josefina and her sisters distrust learning to read and write, as well as other changes their Tía Dolores is bringing to the household, because they fear they will lose their memories of their mother.

Lost in the Black Forest, Otto meets three mysterious sisters and finds himself entwined in a puzzling quest involving a prophecy, a promise, and a harmonica. Decades later, as the second World War approaches, the lives of three children -- Friedrich in Germany, Mike in Pennsylvania, and Ivy in California -- become interwoven when the very same harmonica lands in their lives. All the children face daunting challenges: rescuing a father, protecting...