The story's protagonist is Dan Harland who, as a young man, was set upon by a famous gunfighter and, whether through accident or latent skill, outdrew and killed him, earning himself an instant reputation, one which he is then forced--for years--to defend simply to defend his life as others seek to make their own fame by killing him. He never asked for nor wanted this life, and repeatedly tried to escape it, until finally giving in and deciding the universe wants him to be a killer. On his first "job", however, the man he's paid to kill actually outdraws Dan, which has never happened before, only he doesn't fire and allows Dan to kill him. This upsets Dan immensely, for reasons which surprise him, and he's determined to learn why he was hired to kill this man (as he was hired through a proxy) and what had done to warrant his death.
What follows is modest mystery of lies, love and greed revolving around money--what else?--and unfaithful spouses. It's a story that could have easily been set in a more modern time period, in a more urban environment, but works surprisingly well in a western setting.
It's also about the weight of murder, how such a simple act is so profound and how a killer can suffer as much as any other survivor. Dan Harland is not a good person, we're shown that by De Rosso right off the bat. He's done terrible things and while exactly wracked with guilt over the people he's killed, he wants to be better than he is and trying to avenge a man he himself killed, as crazy as that sounds, is the first step in the process as far as he's concerned.
Simply put, the story is fantastic and I loved it. The drawback to the book, however, is that the prose is relatively weak. I don't know how established an author De Rosso was when this was published, but the quality of writing doesn't match the storytelling ability. The prose is simplistic and oftentimes repetitive, as if De Rosso hit on phrases he felt comfortable with and couldn't resist using over and over again to the point where it was noticeable.
Don't let that flaw dissuade you, though; while it does take a little getting used to, the strength of the story quickly makes up for any technical deficiencies and I very much recommend it if you can get your hands on a copy.