Question about chronicles of narnia?

The book The Horse and His Boy takes place during Peter, Susan, Lucy, and Edmund's reign as High Kings and Queens of Narnia. Also, in The Last Battle,in an ogy to Judgement Day in christianity, the four return not as real people, but as spirit versions of themselves. Hope that helps! My advice is to read the books, they have things the movies simply didn't have enough time to include.