In all of these, interaction between the minuscule Borrowers, who are themselves supposed to be descendants of the folkloric little people, and the "human beans" (a mispronunciation of "human beings") is seen as the primary cause of trouble, irrespective of the human's motives. Whether the main character, Arrietty Clock, has been talking with the ward of Firbank, with Tom Goodenough, or with Miss Menzies, her parents react with similar fears and worries.

As a result of Arrietty's illicit talks, her family is forced several times to move their home from one place to the other, making their lives more adventurous than the average Borrower would like. They finally settle down in the vicinity of a church, in the home of a caretaker surnamed Whitlace (or "Witless" as his undiscovered tenants call him).

Along the way, they meet a cast of colourful characters, such as a hunter of their own race whose only memory of his family is the adjective "Dreadful Spiller" which he uses as a name; other Borrowers such as their relations the Harpsichords and one Peregrine ("Peagreen") Overmantel; also Big People such as Mild Eye the Gypsy, Tom Goodenough the gardener's son, and "Her" (Great Aunt Sophy).