Much as I loved "That Hideous Strength" and the Narnia books, "Til We Have Faces" blows them all out of the water. It is far and away C.S. Lewis' best piece of fiction. It also presents a more mature, more personal and more honest look at the nature of suffering than his previous book to deal with the subject, "The Problem of Pain."
The main character, Queen Orual, writes the first part of the book as a complaint against the gods because they are cruel to men beyond reason and without excuse. They take away from us everything that ever gave us happiness, and make it so that we often appear to be to blame for our own misery. (In her case, she had the misfortune of being one of the sisters in the Cupid and Psyche myth.)
In the second part of the book, she gets to deliver her complaint against the gods, and is answered.
Fantastic reading. I re-read it after Lumpy moved back to his parents, and found it made much more sense than it had the first time I read it, years earlier.