Well... it wasn't as bad as I expected.
I was fully anticipating a Philippa Gregory wanna-be (and I HATE Philippa Gregory), and it turns out Bower is a better writer than Gregory (not hard), but I couldn't figure out for the life of me what story Bower was telling or why she wanted to tell it.
The plot, such as it is: an impossibly beautiful blond blue-eyed Spanish Jewess (I just report this stuff, people) is sort of sold by her father to be a lady-in-waiting to Lucrezia Borgia (no, I didn't understand the transaction aspect of it at all, or what her father got out of it), and must convert to Christianity. She does, because she doesn't really care about being Jewish, and there are later clumsy attempts to make her care, but she just comes off as not thinking seriously about religion at all, which is fairly anachronistic.
Our heroine, who we are repeatedly told is brilliant and irresistible (told, not shown), falls in love with Cesare Borgia, Lucrezia's brother, and bears him a child. Most of the book is her mooning after him while other characters tell her to grow up.
The "holy cow, incest!" revelation about Lucrezia and Cesare is not a revelation to anyone who knows anything about the Borgias, so when it's finally trotted out on page 512, I was not impressed. It only drove home the fact that our heroine is not very bright, given that she's failed to figure this out earlier.
None of the characters are more than two-dimensional, and I had a very hard time telling the minor characters apart. Bower's one stroke of originality is that Cesare infects our heroine with syphilis and she dies from it, instead of marrying the ugly-but-sweet man who is willing to take her, illegitimate child and heart given to another man and all. Seriously, has there ever been someone in real life who would say, "I don't care that you're in love with someone else; I am happy just to be close to you and have sex with you knowing you're thinking about him and hold you when you cry for him..." Seriously? And would that actually be appealing? Lord, no. So why does that character show up ALL THE TIME in these sorts of books? Oh, right, to prove how gloriously irresistible our heroine is. Gag.
Next up: Game Six: Cincinnati, Boston, and the 1975 World Series: The Triumph of America's Pastime, by Mark Frost. Bit of a change of pace, there!