Lud-in-the-Mist, the capital city of the small country Dorimare, is a port at the confluence of two rivers, the Dapple and the Dawl. The Dapple has its origin beyond the Debatable Hills to the west of Lud-in-the-Mist, in Fairyland. In the days of Duke Aubrey, some centuries earlier, fairy things had been looked upon with reverence, and fairy fruit was brought down the Dapple and enjoyed by the people of Dorimare. But after Duke Aubrey had been expelled from Dorimare by the burghers, the eating of fairy fruit came to be regarded as a crime, and anything related to Fairyland was unspeakable. Now, when his son Ranulph is believed to have eaten fairy fruit, Nathaniel Chanticleer, the mayor of Lud-in-the-Mist, finds himself looking into old mysteries in order to save his son and the people of his city.

(From Goodreads)