Part of the Piper Green and the Fairy Tree chapter book series. In this third installment, Piper wishes for a horse after seeing one delivered to the island where she lives, but the fairy tree gives her a whistle instead. The plot meanders, but it all comes together in the end. Piper seems a bit more ADD-ish in this story than in previous books of this series. Interesting information about lobster fishing is worked into the story.