I found A Green and Ancient Light by Frederic S. Durbin in the adult section of the library. It is a fantasy that will become a classic one day. It is one of the best books that I have read in a long time. It is suitable in every way for a third grade classroom all the way up through high school. The book is centered around a young boy who is sent to stay with his Grandmother over the summer during war time. The country, the time period, the names are all mysteries to create a story that could be anytime, any country fighting any other country. Readers are not allowed to pick sides in the war. That is not what the story is about. The story is about loyalty, love, and sacrifice. It's about honesty and trust. And it's about loss.
The young boy and his grandmother work on a puzzle that appears in an ancient garden. In the meanwhile an enemy soldier's plane crashes near the garden. The grandmother patches up the soldier even though he's the enemy. And because she helps the soldier, the soldier lives to help the young boy and his grandmother. This story is full of metaphor. It is thoughtful and kind and beautiful. It would be an excellent story, much in the line of the Lion and the Wardrobe but kinder and gentler.
I would use this book to teach diversity and tolerance. A lesson plan might include discussions of the reasons why the author left the names of the characters out of the book. The riddles of garden can be expanded to discussions of stars and constellations or myths. Or this book could just be enjoyed in order to make students lifelong readers.