The themes are gender, beauty, identity and power, what it means to have control, and what it means to be an object. It's dark and searing, not dark in say an Oryx and Crake kind of way -- that one I had to put down -- but dark in a "this is forcing me to face up to a lot of things I thought I was good at ignoring" kind of way. One of the themes Egan explores that I don't think I've read about before, ever, is the contempt beautiful women have for women who are not attractive, and vice versa. I spent a lot of my life pretending that didn't exist, but it does, and she nails it. She also takes a deep dark look into the advantages beautiful women have in life, and the ones they really do not. There's a great scene where one of the main characters, a 35-year-old former model, sees a young model walking down the street in Manhattan, watches the power the young woman thinks she has in her ability to attract so many male gazes everywhere she goes. And she remembers how she, too, once thought that's what power was, having other people own and control you because of this fleeting quality, and how now she knows real power comes from what you say and do, from autonomy, not from who owns you and how much money they have.
There are a lot of flat and unrealistic elements to this novel, but I really don't care. It's incredibly engrossing, and it has really made me think.