Keller possesses all the qualities of a professional killer. He's cool, confident, reclusive, icy, and ruthlessly efficient. But this seasoned hit man is also prone to self-doubt as he finds himself caught in the clutches of a mid-life crisis.
The Forgotten, by David Baldacci (adult fiction, Overdrive ebook). After he receives a posthumous note from his aunt hinting that things are horribly amiss in her Florida Gulf Coast town, Army Special Agent John Puller uncovers a shocking conspiracy.