The Clock family are four-inch-tall people who live anonymously in another family's residence, borrowing simple items to make their home. Life changes for the Clocks when their teenage daughter, Arrietty, is discovered.

Piper moves to New York for a fresh start, there she meets Austin an aspiring writer. The magic of the autumn season brings them close together. They team up on a children's book project during which they come to a great realization.