Captivated by You: Crossfire Series, Book 4 by Sylvia Day

The #1 New York Times and #1 USA Today bestseller. Gideon calls me his angel, but he's the miracle in my life. My gorgeous, wounded warrior, so determined to slay my demons while refusing to face his own. The vows we'd exchanged should have bound us tighter than blood and flesh. Instead they opened old wounds, exposed pain and insecurities, and lured bitter enemies out of the shadows. I felt him slipping from my grasp, my greatest fears becoming my reality, my love tested in ways I wasn't sure I was strong enough to bear. At the brightest time in our lives, the darkness of his past encroached and threatened everything we'd worked so hard for. We faced a terrible choice: the familiar safety of the lives we'd had before each other or the fight for a future that suddenly seemed an impossible and hopeless dream...