Jack Reacher has been helping people for a long time now and he does not need any kind of reward from anyone. He helps people because he likes helping the innocent and serving justice in the process too. Jack is not the type of man who has ever done anything for the sake of money.
He wanders here are there just like we saw him in No Plan B and Night School so there is no proper motive for his living. Lee Child has painted Jack as a guardian angel who is always there when someone needs him the most. He can even hear the whispers like a demigod. This time he was just going alongside the road when he gets the lift from a woman named Carmer Greer.
The woman was a ravishing beauty but Jack was not tempted by these sorts of things and he was more interested in the story which the woman was telling him. The woman tells Jack about her house, family, and hometown in which she was living. There were dangerous people after her and she is not going to survive if she tries to save her husband alone.
Still, she is not going to stop at any rate because she wants to save her husband so that she can live a normal and happy life once again. Dick Hill narrates as Jack Reacher instead of stopping the woman joins her in her quest because he has all the time in the world to reach his own destination. Both of the characters can die during the struggle but they are not those who get scared of little things.