You could substitute one of the Grades 10-12 books. The King’s Fifth and The Lantern Bearers are both really good and definitely accessible for those ages. You could also try Son of Charlemagne by Barbara Willard. I also really like Gabriel and the Hour Book from Yesterday’s Classics. You might be able to find that one for free. It might be a little young for 9th grade, but I really enjoyed it.
