A radio journalist, whose sister asks him to look after her son, takes his nephew along on his travels around the country.

Frank Adler is a single man raising a child prodigy, his spirited young niece Mary, in a coastal town in Florida. Frank's plans for a normal school life for Mary are foiled when the seven-year-old's mathematical abilities come to the attention of Frank's formidable mother Evelyn, whose plans for her granddaughter threaten to separate Frank and Mary.