Logan made a deathbed promise in Iraq to his best friend and brother-in-arms, Billy. Now, years later, Billy's kid sister Shae is in trouble, and Logan needs to make good on his vow. The only problem is Shae's not a little girl any longer, but a grown woman who can take care of herself.Every year on Billy's birthday, Shae gets a call from his best friend Logan. They've never met in person, and the call is a reminder of how much Billy's loss means to her and to Logan.This year, things are different. Shae's in trouble, and she really needs someone to listen to her and tell her she's not crazy or imagining things. Logan is the one person who might be able to help her.But getting involved with Logan could be the biggest mistake she's ever made. He's ex-Special Forces, a man who killed for his country. Her father hates Logan and blames him for Billy's death. And though she's only seen Logan in her brother's high school photos, he was her teenage crush.Logan will do anything to keep his promise to Billy. She needs him and his skills. But Shae's in the "little sister" zone and off limits, right?Tell that to Logan's body and to his heart.