Some years ago, I read Planet Narnia: the seven heavens in the imagination of C. S. Lewis, which argues that the seven Chronicles of Narnia correspond to the seven classical heavenly bodies. It’s an attractive and plausible theory, and I think that’s as far as I’ll go.
Anyway, if we’re to believe the author, Michael Ward, The Voyage of the Dawn Treader is associated with the Sun, and that’s good enough for me to include this book for this prompt. Even if it weren’t, there’s the Sun front and centre on Caspian’s tunic.
It’s my favourite of the Narnia books, and has one of the best opening lines of all time.
There was a boy called Eustace Clarence Scrubb, and he almost deserved it.