Buy a Bullet (Orphan X #1.5) by Gregg Hurwitz

The Nowhere Man is a figure shrouded in secrecy—a near legendary figure who helps those lucky few who are given the means to reach out to him.

Before he was the Nowhere Man, Evan Smoak was a highly trained government operative known to a few as Orphan X.

This is the story of Smoak's first outing as the Nowhere Man, where after completing a mission in Northern California, he happens to spot a young woman at a coffee shop. Brutalized and under the control of a very powerful, unscrupulous man, her life is in danger if she doesn't escape. And the only person that can help her do that is a man with the background and skills of the Nowhere Man.