FBI/CIA operation, surveil. of husband who seems to be killed in explosion. wife survives

At the beginning of the book, they introduce you to a woman who is hosting a dinner party with her husband (whom they paint as powerful, but distant, and she is clearly the 'trophy wife') Very soon, there is an explosion, and she is very badly injured. Turns out, the husband was under surveilance, and she was rescued by them (either CIA or FBI). She had to undergo plastic surgery on her face, and spent a bit of time recovering in the hospital, before they released her to the agent that was working the case. He took her to his (ranch?) in Montana to recover and see if she could remember anything that would help them or lead them to the people her husband was working with - that is when she learned that her husband was not who she thought he was and that her life was a lie. Of course, then it turns into a bit of a 'love story' where the agent knows he shouldn't fall for her, but she's so perfect (of course). Eventually they get a lead but they can't send anyone in to get anything except her going undercover as a model and that is when she discovers the husband she thought was a dead bad guy is an alive bad guy.