Tolkien's lectures on fairy stories. Until I cobble together a few thoughts for a future blog post, I'll leave you with this quote. The words in italics are words that Tolkien himself coined.
The consolation of fairy stories, the joy of the happy ending: or more correctly of the "good catastrophe," (a eucatastrophe) the sudden joyous 'turn' (for there is no true end to any fairy tale): this joy, which is one of the things which fairy stories can produce supremely well, is not essentially 'escapist' nor 'fugitive.' In its other-world setting, it is a sudden and miraculous grace: never to be counted on to recur. It does not deny the existence of dyscatastrophe, of sorrow and failure; the possibility of these is necessary to the joy of deliverance. It denies (in the face of much evidence) universal final defeat and in so far is evangelium, giving a fleeting glimpse of Joy, Joy beyond the walls of the world, poignant as grief. (p. 75)