Tolkien says it best: «It is the mark
of a good fairy - story,
of the higher or more complete kind, that however wild its
events, however fantastic or
terrible the adventures, it can give to child or man that hears it, when the «
turn» comes, a catch
of the breath, a beat and lifting
of the heart, near to (or indeed accompanied by) tears, as keen as that given by any form
of literary art... In such stories, when the sudden «
turn» comes we get a piercing glimpse
of joy, and heart's desire, that for a moment passes outside the frame, rends indeed the very web
of story, and lets a gleam come through.»