Knot Gneiss

Wenda Woodwife has a knotty problem--her mood swings have sent her beloved husband, Prince Charming, off on Adventure. She seeks the cure from the Good Magician Humphrey, only to discover that he has a knotty problem of his own and that only Wenda Woodwife can help him. 
She'll need Companions. Luckily, in Xanth magical companions are never far away, and all roads lead to Adventure. 
This 34th installment in the saga of the magical land of Xanth proves the enduring appeal of Piers Anthony's peerless creation.