Leroy Silver is an agent with an unnamed American Intelligence agency.
His role in that organization is simple - he kills people.
The government department has its headquarters, at least the 20-story building where Silver's handler works and where security is extremely tight making just showing up for a meeting a very involved process, is in New York City which is significant only in that it is not in the nation's capital.
Silver's boss is Captain Matt Anderson who "had been Silver's handler ever since he got assigned to the arm of the government responsible for fixing the country's messes. Silver worked for a secret unit that very few people knew existed. Their job was to eliminate some of the world's most dangerous and influential people, preventing them from risking or taking the lives of the country's citizens. After they recruited Silver from the army, Captain Anderson took him under his wings. He was one of the few people Silver could call a friend."
Now all that is important as a backstory pretty much because when we first meet Silver, he has been ordered to kill a very bad man specializing in selling very bad armaments to very, very bad terrorists and such. Silver has no qualms whatsoever about eliminating this fellow because he deserves it and Silver has killed a good number of such people over the years. What causes the problem in this instance is the specific instructions to shoot the man in the head during the high school graduation ceremony for the victim's daughter. Silver knows he can do it - he is very good at his job - but the idea of ruining the girl's special moment like that, not to mention all the other people in attendance was not to Silver's liking and he decides to not do it.
Which is why very shortly after we meet him, he is fired. Out of a job he has had for quite a few years. All alone, pretty much, too, because he grew up in the foster care system and had no one else. Except for Julia, a bartender at his favorite NYC establishment who he knew only as his friendly mixologist (though that will change).
We get to watch Silver, a tall, athletic and quite handsome black man, change his life completely as he is forced to get a job as a security expert and his type of work will be different than shooting very bad people but not that different. There are a whole lot of very bad people out there and Silver seems quite good at finding them.
And through it all, there is Julia; one very special lady.