The Silencer by Mike Ryan
CIA Black Ops agent John Smith is on his latest assignment in London. Little does he know–it’ll also be his last. Barely surviving an attack on his life, Smith lays low for six months until he returns to the United States. His flight is strangely diverted to Philadelphia where he meets a mysterious man who already knows about his past and recruits him for a job.
Needing a new identity, Smith becomes Michael Recker. He tries to prevent bad things happening to innocent people while also interacting with several crime factions who are battling for control over the city. All the while, Recker begins to plan his revenge on Agent 17, who is responsible for a heinous act that Recker will never forget.