Dorothy and her friends, both old and new, return to Oz in this illustrated whimsical adventure. In this graphic adaptation of Baum's fourth novel in the Oz series, Dorothy, her kitten, her cousin and his horse find themselves in a cavernous world deep within the Earth after an earthquake. Trapped in the land of the Mangaboos, a race of emotionless vegetables, the assemblage must find a way out before they are disposed of, as the vegetable people think that they caused stones to rain upon them. Serendipitously, the group encounters the kindly Wizard (also a victim of the quake), and an episodic series of adventures ensues before Ozma conveniently whisks them to Oz via a magical belt at a greatly opportune moment. Back in Oz, they suffer a silly trial of Dorothy's kitten before all can be righted and both Dorothy and her cousin can return to their proper homes. Shanower's dialogical adaptation is good fun, especially coupled with Young's pleasantly playful and vibrant art. Full of whimsy, it captures the spirit of the original story. Adaptations of classics can be thorny; this one is a particularly well-conceived effort and may well entice readers to seek out the original sources. An enjoyable continuation of the series, it raises high hopes for the subsequent volumes. (Graphic adaptation. 10 & up)