Dor is tasked with standing in as king of Xanth, while King Trent and Queen Iris make a trip to Mundania to establish trade. Dor, with the help of his friends, is able to solve day-to-day problems in the kingdom. But the when the scheduled time for the king and queen arrives, they are nowhere to be found. Weeks pass, so Dor goes to see Humfrey, the magician of information. Dor must win entry to the castle, but Humfrey tells him that he has discovered a Magician-class centaur, with a yet-unknown talent. Before searching for Trent and Iris, Dor must travel to Centaur Isle to find the centaur magician, but first he must perform the wedding ceremony for Gorgon and Humfrey. Many visitors have arrived to see Humfrey get what he deserves. After Dor stumbles through the ceremony, Jonathan agrees t