The Hard Line (Gray Man)

For a man who works in the shadows, a family is not just a luxury - it's a weakness. When an unknown enemy uses threats against Zack Hightower's estranged daughter to blackmail the injured operative into taking on a dangerous mission, his friend, Court Gentry, aka the Gray Man, volunteers to take Zack's place.

But Court has problems of his own. He's already got a expert assassin on his trail for no apparent reason. And now his quest to protect Zack's family may drag his own family into the maelstrom.

There's one lesson that Court has found undeniable: There's a reason superheroes have secret identities.