This certainly isn't a book for everyone. It deals with child loss. Baby loss/SIDS, to be more specific, and what it does to a family. It also deals with infidelity, divorce, and step-parenting.
I think though that Ayelet Waldman does an amazing job in making the main character's guilt and grief real. And I think that is what sucks you in as a reader and makes the book so hard to put down.
The other characters are interesting too. There is the overprotective OB/GYN ex-wife who delivers every one of her patient's babies, the 5-year old stepson who is sometimes too smart for his own good, and of course the law partner husband who finds himself in the middle of it all.
As an aside, one of the things that I thought was cool is that although most of the book takes place in Manhattan, the city of Emeryville, California, is mentioned. It turns out that the author lives in Berkeley. B thinks he may have seen her browsing at Cody's one day with her husband, who is also an author.