Uncle Henry has been ordered by his doctor to take a vacation from his Kansas farm to Australia. He and his niece Dorothy Gale (this is the first of the Oz books in which the reader learns her last name) are aboard a steamship traveling there when they are caught in a fierce storm and separated. Dorothy is tossed overboard in a large poultry crate along with Billina, a yellow hen that was also on the ship.
It is the first Oz book where the majority of the action takes place outside of the Land of Oz. Only the final two chapters take place in Oz itself. This reflects a subtle change in theme: in the first book, Oz is the dangerous land through which Dorothy must win her way back to Kansas; in the third, Oz is the end and aim of the book. Dorothy's desire to return home is not as desperate as in the first book, and it is her uncle's need for her rather than hers for him that makes her return.
It was the first in which Baum was clearly intending a series of Oz books.
