The Castle of Llyr

In 'The Castle of Llyr', the third book of The Chronicles of Prydain series by Lloyd Alexander, the story follows the adventures of Taran, the Assistant Pig-Keeper, and his friends as they embark on a quest to protect Princess Eilonwy, a friend and one of the main characters. Eilonwy is sent to the Isle of Mona to learn how to be a proper lady, but her magical heritage as a descendant of the enchantress Llyr puts her in danger. The evil sorcerer Achren seeks to use Eilonwy's powers for her own nefarious purposes. Taran, along with the bard Fflewddur Fflam, the loyal creature Gurgi, and the prince of Mona, Rhun, must navigate various challenges and confront Achren to save Eilonwy. Throughout the journey, Taran learns valuable lessons about heroism, friendship, and self-discovery.