The Attack by Yasmina Khadra
Arab-Israeli surgeon Amin Jaafari, a prominent physician in Tel Aviv, is told his wife, Sihem, is responsible for a suicide bombing that killed seventeen people, including many children. He knows that can't be true, that Sihem is actually one of the victims.
Then Amin receives the letter Sihem sent to him the day before the attack.
On Amin's subsequent search for the truth about the wife he thought he knew, the reader sees a man's life completely unravel against the backdrop of the Palestinian-Israeli conflict. The ending, which I didn't see coming until it slammed into me, isn't ever going to leave me.
See this author interview on Blogcritics to learn more about Khadra.
My overall rating of The Attack is an A. I'm off to read Khadra's The Swallows of Kabul next.