Protecting His Best Friend's Sister was originally published as Duty Bound. It has since been expanded, revised, and re-edited. The only woman I want is the one I can never have. Harper. My best friend's sister. I've wanted her since I was eighteen, but she's always been off-limits. Now I'm home after years in the Marines, and nothing has changed—except everything has. Her brother is dead, and she's on a hopeless quest for answers about his death. And I want her just as much as ever. Someone is trying to kill her now, and she won't let me keep her safe. I have to protect her 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. And Harper has always been precious to me.