This is now one of my favorite retellings. Lewis offers a stunningly complex characterization; the story of Psyche and Eros, told from the point of view of one of the "ugly sisters." And, honestly, I was blown away by this. I have a tendency to get caught up with the newest releases and think of everything published before 1960 (sorry!) as "old fashioned, heavy prose." This book is one of the best books I've ever read--being both in my favorite category of story and amazingly, beautifully written.
I cannot recommend this enough. Whether or not you like the Narnia books, if you love mythology and retellings, you need to read this book.