As the inhabitants of the island of Mistmantle prepare for the coronation of Crispin the squirrel, robes are stitched, cakes are baked, wine is brought up from cellars, and the Heartstone—the unique gold-and-silver-flecked stone that only the rightful ruler of the island can hold—is readied.

But the newly established peace in Mistmantle is soon under threat. A storm-ravaged ship from a distant land appears in the mist surrounding the island; a dramatic revelation about the revered Heartstone comes to light; and the extrasensory powers of a young islander reveal the evil close at hand.

Urchin finds himself journeying to a hostile island, where the maniacal King Silverbirch and his sorcerer, Smokewreath, await him. There, Urchin will have to face challenges greater than those her has ever known, and in so doing, he will learn a secret about his past that will change his life forever.