One morning in 1930, twelve-year-old Ellie Mae Williams wakes to discover that her father has lost his job. Ellie doesn't want her friends to know of her father's unemployment, but it soon becomes common knowledge as her family plunges into financial hardship during the Great Depression. The family must cut the extras out of their life and do odd jobs to make money. Ellie quits her piano lessons, her mother takes in washing, and her father raises chickens.

During the summer, Ellie goes swimming with her friends, helps her parents around the house, and tries to adjust to a lifestyle bordering on poverty. When she receives a mysterious letter postmarked from Chicago with no return address, Ellie is surprised to find only a sheet of music inside. She plays the piece and soon receives another letter encouraging her to continue practicing her piano.

Although the family doesn't have much money for Christmas, there are presents for the children, a delicious roast chicken, and a real Christmas tree. Ellie still continues to practice her piano, and when the new year dawns, she receives another package from Chicago containing more music. Will Ellie discover the sender's identity or will it remain a mystery?