Duty Bound // Protecting His Best Friend's Sister

I used to think I could be a hero, but one deadly night destroyed that delusion. So I've come home defeated. My military career, my best friend, my purpose--all of it is lost. What I find is her. She's my best friend's sister, and she's everything I shouldn't want. She's on a hopeless quest for answers about her brother's death, but those are secrets that can never come to light. She's always been a fighter, and she desperately wants the truth. I desperately want her. Someone is trying to kill her now, and she won't let me keep her safe. I have to do it anyway, even if she doesn't trust me, even if she hates me for it. A man protects what's precious to him, whether or not he can ever claim her for his own. So she becomes my purpose. I'll become a hero for her.