The Hard Way (Jack Reacher 10) by Lee Child
Used mass market paperback book (cover may differ)
Jack Reacher was alone, the way he liked it, soaking up the hot, electric New York City night, watching a man cross the street to a parked Mercedes and drive it away. The car contained one million dollars in ransom money because Edward Lane, the man who paid it, would do anything to get his family back.
Lane runs a highly illegal soldiers-for-hire operation. He will use any tool to find his beautiful wife and child. And Jack Reacher is the best manhunter in the world.
On the trail of vicious kidnappers, Reacher learns the chilling secrets of his employer's past . . . and of a horrific drama in the heart of a nasty little war. He knows that Edward Lane is hiding something. Something dirty. Something big. But Reacher also knows this: He's already in way too deep to stop now. And if he has to do it the hard way, he will.