What a delightful find.  This was the last book published by Tolkein before he died.  The whole story arose out of his "failed" attempt to write an introduction to George MacDonald's Golden Key.  I say failed because he never did finish writing it but here is the reason why: he decided that people should be introduced to a fairy tale by the tale itself.

Anyway, this is a small book that is typical Tolkein as the story will delight young readers while older readers will find food-for-thought in its pages.  The ending is an interesting mix of sweetness and sadness, such as it should be in a story about "faery".