This book is called The Silver Chair. It is about Peter's, Susan's, Edmund's, and Lucy's cousin Eustuce. She was called back to Narnia by Aslan with their new friend Jill to go on a quest to find King Caspian's son who disappears the day of a serpent attack and the queen's death. My favorite part was when Eustuse and Jill where on there quest when they came come into a kingdom which happens to be a home for giants. They stay there. They figured they where trying to cook them for a meal. If you like adventure or fantasy books I think you will like this book.