This would be the most perfect TV show ever made. Agent Graves contacts a person who's the victim of some horrible wrong. He hands them documentation on who is ultimately responsible for this wrong, a hand gun, and 100 untraceable bullets. There is no penalty for not taking the gun. There's no reward for taking it either. Each person must weigh if the person that has hurt them so is worth killing.
That's why it's beautiful TV. Each episode is basically a mini play of morality told in a brutal noir style. Will the person take the gun? If they do, can they do the deed? Will it blow back horribly on them. With Agent Graves as the only reoccurring character (at least at first) anything can happen in these stories.
There is also the deeper mystery of Agent Graves. Who does he represent? Why are they passing out untraceable guns and ammo? These questions (at least in the comic book) do get answered, but all in due time. HBO are you listening?