"The Silver Chair" by C.S. Lewis. Short Brief
A search for a missing prince, a gloomy Marshwiggle, chatty owls, human-eating giants, an underground civilization, a witch, magic, and enchantments. It's all there, and more. Eustace and Jill set out with Puddleglum, the Marshwiggle, to find Prince Rillian, son of Caspian the Tenth. The story is packed subtleties and witticisms that will please younger readers, and cause adults to pause and ponder. I recorded myself reading each chapter, and uploaded them to my channel on YouTube at Michael Philliber . I happily recommend the book.