Dor is growing up and King Trent is providing him with occasional opportunities to practice his Kingship skills as we all know from previous books that Dor is the designated heir for King Trent. So, at the beginning of the book, King Trent informs Dor that he will be going on a secret trade mission to Mundania and Dor needs to take over the Kingship while Trent is away. To camouflage everything, Trent tells everyone that he and Iris are taking a long needed vacation. The whole absence is supposed to be for only a week.
Dor takes over and finds out that being a King is not as easy as it seems. As a matter of fact, there are implications and complications for every seemingly minor decision that is brought to Dor's attention. So, Dor does the best he can and seems to do a fair job of it especially since his magical talent is very helpful! The week passes by and Dor is ready the give up his throne ... but Trent does not return!!!
Another two weeks pass by and Dor is beside himself with worry. Not only that, but Trent's daughter Irene is also sick with worry and since she is Dor's constant companion, it is hard for him to ignore the issue. Another factor that complicates life is that Dor is now 16 and Irene is 15 and she is developing into quite a beautiful girl while Dor is also developing into a man and is starting to notice that Irene has developed in some very interesting shapes and intriguing ways!
Finally, Dor and Irene cannot stand it any more and they resolve to search out where Trent is and rescue him if necessary. But, another complication arises, it seems that a new Magician has been detected in the very south of Xanth and that needs to be investigated immediately. This is especially important since the furthest southern point of Xanth is inhabited by Centaurs - it is called Centaur Isle - who believe that magic is obscene. With the potential complications of all of this, Dor and Irene collect their friends (Chester the Centaur, Grundy the Golem, and Smash the Ogre) and go off to check out what is going on in the south.
As is usual with Xanth stories, there are many marvelous and dangerous creatures that are encountered and many situations where the play on words leads to some wonderful imagery (for instance, light bulbs are planted in the fields and the brightest bulbs are the most desirable). In this case, Centaur Isle leads to the magic-infused Centaur whose magical talent is the creation of an aisle of magic in front and behind him. In other words, a Centaur Aisle! Dor is also a very creative speller and many people use this attribute when giving him hints. For instance, Trent tells Dor to always rely on his Honesty when needing to make a decision on where to do. This does not make sense to anyone until Dor writes it down as ONESTI which then is revealed as a kingdom in Mundania!
Adventure after adventure result and the happy crew goes from discovering the magical Centaur to finding where Trent and Iris are being held captive. It takes quite a bit of ingenuity and inventiveness on the part of Dor, Irene and Grundy to find Trent and Iris and release them and then set the world aright.
This is a standard Xanth book in its creativity, its word play, and its humor. The storyline itself is dead-serious of course, and the resolution leads to many other possible followups. It is a very enjoyable and quick read - a perfect story for the beach or if you are a commuter!