Sky Island, one of L. Frank Baum’s very best fantasy novels. It tells the further adventures of Trot and Cap’n Bill, the little girl and one-legged old sailor Baum introduced in Sea Fairies, with the addition of Button-Bright and Polychrome from The Road to Oz. Unlike those books, Sky Island has a real plot.
However, it didn’t earn Baum as much as he wanted, so for his next fantasy novel he returned to the Oz series. Eventually he merged the two series by bringing Trot, Cap’n Bill, and Button-Bright to the Emerald City, but since Sea Fairies and Sky Island don ’t have the word “Oz” in their title they’ve never attracted so many readers. In the latter case, that’s a shame.
Last May, artist Kevin Merriman posted some unusual character designs for Button-Bright and Trot. Check out the link for his take on Cap’n Bill as well.