Grampa in Oz

Grampa in Oz is the eighteenth book in the Oz series created by L. Frank Baum and his successors, and the fourth written by Ruth Plumly Thompson. Unlike in Baum's books, Grampa in Oz presents a kingdom in Oz that has a monetary economy, and is on the verge of economic collapse. It was followed by The Lost King of Oz.

Plot

Things are going from bad to worse in the dilapidated kingdom of Ragbad; even the rag crop is failing. To top it all off, King Fumbo's head is blown away in a ferocious storm. Prince Tatters of Ragbad, and Grampa, a former soldier and the bravest man in the kingdom, set out on a three-fold quest: for King Fumbo's lost head, a fortune to save the bankrupt kingdom, and a princess for Tatters to marry. They are joined by Bill, an iron weathercock from Chicago, who was brought to life by an electrical storm and blown to Oz.
Meanwhile, in Perhaps City in the Maybe Mountains, the Princess Pretty Good has a problem: the prophet Abrog foresees her marrying a monster if she does not marry in four days. When Pretty Good resists, Abrog kidnaps her and tries to transform her into a clod of earth; but since she is, in fact, more than just pretty good, as princesses go, Pretty Good turns into the beautiful flower fairy Urtha.
Wide-ranging adventures — from Fire Island to Isa Poso to Monday Mountain — culminate in the location and restoration of King Fumbo's head. Dorothy manages to restore order. Prince Tatters ends up married to Princess Pretty Good — which is pretty good for him.