Synopsis:

  Most Oz fans are mystery fans, too... so here is an Oz mystery that is all tangled up in three strands of emeralds and the strange magic that lies in the depths of their stones. Originally intended as gift for a wood nymph named Lorna, they instead fall into evil hands.

  The story starts in Skampavia (a poor and tiny country outside of Oz near the Land of Ev) where Skamperoo – an ambitious and discontented king – decides to take three emerald necklaces from a scoundrel merchant named Matiah (who actually had found them after they had been discarded by a squirrel). Matiah makes his way into the castle, convincing Skamperoo of the enchantment of the stolen stones and of the fact that only he can work their magic.

  When the king wishes for a white charger, everybody (including Matiah) is surprised when a white horse drops out of the sky – Chalk, the magnificent Wishing Horse of Oz. Well, when Skamperoo realizes that the magical emerald strands must surely come from the Emerald City, he decides to become king of all Oz.

  He succeeds for a time by making everyone in Oz forget Ozma, the Wizard, and the other rulers of the land (who actually all disappear). Everyone that is except for Dorothy who senses that something has gone wrong. Maybe it's because the whiskers of the Oz Army – that is, the whiskers of the famous Soldier with the Green Whiskers – have suddenly turned RED!. With the help of Pigasus, the winged flying pig (originally introduced in The Pirates in Oz) Dorothy sets out to save Oz.

  Gloma, the (good) Black Queen of the Black Forest (in the otherwise yellow Winkie Country) grants Dorothy the magical gift of darkness to aid her in her efforts to overcome Skamperoo and Chalk. Of course, Dorothy must first tangle with Kaliko (the current Gnome King) and his minions – after all, Gnome kings seem to have the upper hand at their single-sighted mission to become the King of Oz. This time out, Kaliko is teamed with the disagreeable Dooners – who tie people up with seaweed and pelt them with sand balls.

  The end is near when Dorothy and Pigasus encounter Bitty Bit, the Seer of Some Summit and together with Chalk's good horse sense, the missing rulers of Oz are freed from their enchantment in Thunder Mountain and Skamperoo is sent contentedly back to Skampavia.

  Note: After 29 titles and 35 years of Oz tales, public demand was beginning to wane. Reilly & Lee's new president was not an Oz fan and consequently marketing and promotion was not what it used to be. 1935's The Wishing Horse of Oz is the last Oz title with color plates (the reprints of earlier tales had already resorted to black & white) and production was so rushed that John R. Neill either forgot or didn't have time to draw endpapers for the first time. Numerous typos abound in this tale.

  Regardless of all of this, Ms. Thompson went on to write four more annual Oz titles, John R. Neill added three annually through 1942 (actually a fourth title, which was nearly complete before his death, was added in 1993).