Robert of Matters Arising recommends C.S. Lewis' Till We Have Faces: A Myth Retold, a novel retelling Apuleius' story of Cupid and Psyche from the point of view of one of Psyche's sisters.
Book description: This tale of two princesses – one beautiful and one unattractive – and of the struggle between sacred and profane love is Lewis’s reworking of the myth of Cupid and Psyche and one of his most enduring works.
The Google Books copy allows a few glimpses into the novel. I found this review:
Lewis considered this, his last novel, to be his best, and many of his readers agree. It is the first-hand story of the ugly princess Orual’s love for her sister, and her complaint against the gods. Orual lives in Glome, a little barbarian kingdom of ancient times. Glome and its closest neighbours are fictional, but Lewis uses his considerable knowledge of classical history to imbue it with all the beauty and horror of pagan culture. read on
I also read on Wikipedia (as usual handle with care) that
"the idea of rewriting the myth of Cupid and Psyche, with the palace invisible, had been in C. S. Lewis's mind ever since he was an undergraduate, and the retelling, as he imagined it, involved writing through the mouth of the elder sister. He tried it different verse-forms during the period when he still thought himself a poet, so that one may say that he had been "at work on Orual for 35 years," even though the version told in the book "was very quickly written." In his pre-Christian days, Lewis would imagine the story with Orual "in the right and the gods in the wrong."[2]
Sounds very tempting. I've put a place-hold on the book at the library and may report.