From the back cover:
Dorothy, the Scarecrow, the Tin Woodman and their new companion Flicker must venture far from the Emerald City to a vast, uncharted, frozen domain, to free Princess Ozma form the clutches of the sorcerous Ice King of Oz!
The third volume in the continuing series of brand new, original, illustrated Oz adventures that critics have touted as "The best Oz books since L. Frank Baum."