Glinda of Oz
by L. Frank Baum (1856 — 1919)
Glinda of Oz is the fourteenth Land of Oz book and is the last one written by the original author L. Frank Baum, although the series was continued after his death by several other authors.
Dorothy and Ozma discover that a war is brewing in a distant and unexplored part of Oz, between two mysterious races, the Flatheads and the Skeezers. The girls set out to try to prevent the fighting, not knowing what dangers await them.