When
Sophie starts school, she notices a flyer for a lecture featuring
Professor Leo Shattenbeg. Could this be their grandfather's missing
cousin, believed to be dead since World War II? At the lecture, Sam
and Sophie discover that Professor Shattenberg has a missing person
of his own-a childhood sweetheart who, like him, had a love of
chocolate. Seeing their chance, the girls offer to help the
professor find his missing sweetheart-all the time running their
own investigation of him.