Rilian is a character from C.S. Lewis's fantasy novel, "The Silver Chair," which is part of the Chronicles of Narnia series. He is the son of King Caspian and is known for being a brave and noble prince. Rilian is initially missing, and his friends embark on a quest to find him, leading them to a series of adventures in the magical land of Narnia. In the story, Rilian is under a spell that causes him to forget his true identity and purpose. With the help of Eustace Scrubb, Jill Pole, and Puddleglum, he ultimately breaks free from the enchantment and reclaims his role as the rightful heir to the throne of Narnia.