Strange changes befall the magical land: the magical power of its inhabitants is weakening, magic is becoming uncontrollable. The former evil wizard, and now the king of Xanth, Trent gives Bink the most difficult task - to find the source of Xanth's magic. So, Bink, a centaur and a soldier turned into a griffin move through the Wilderness, penetrate into a giant underground country, where, according to legend, the great genius Xanth should live...