Die for you by Lisa Unger.
I believe I requested this book because it was mentioned on DorothyL and thought it sounded interesting. And it was interesting, though only in the manner of an assumed identity thriller. It's the story of Isabel Connelly Raine, whose husband Marcus leaves for work one day and never returns. Isabel goes to his office the next day to talk to his business partner, who has not heard from him either. While checking Marcus' desk, she is interrupted by a raid. The group are wearing jackets with FBI on them, but they turn out to be fake. One of them, clubs her over the head and she wakes up in hospital.
When the police inform her that the real Marcus Raine died several years earlier and her husband was an impostor, Isabel takes matters into her own hands to find the truth.
As I said, a fairly typical thriller plot.
What is really wonderful about this book is the prose. Unger comes up with some incredible descriptions of the characters' feelings and thought processes. A description of a feeling Isabel had after her father committed suicide when she was a child:
"It was a strange lightness, a drifting feeling. Zero gravity. I understood that everything that once seemed solid and immovable might just float away."
This book was a real pleasure to read!