Westerns as morality tales have a long history. The classic story of good versus evil is most successful when the characters are well drawn and three dimensional. This is true of classic westerns like The Angel And The Bad Man and it is also true of this Tom Selleck vehicle.
We meet Rafe Covington (Tom Selleck) on a boat where he is in the process of beating the tar out of a sea captain who has apparently killed a crewman - this is all kind of vague and it takes sometime to clarify. What it all boils down to though is that Rafe Covington didn't really know the man in question, he wasn't friends with him, the man just died in his arms the result of an unjust beating. Rafe promised to take care of the man's wife and his ranch.
Okay, so the set up is a little thin, but once you get by the set up what you have is a classic style western that follows the traditional script which slowly and inexorably brings together the villain and the hero. The only slightly, and it is slight, weak link is Mark Harmon as the villain of the story. The problem is that he is so clearly the villain from the first time you see him on screen that there is no real tension as the hero comes to realize what he audience already knows. A great story allows the audience and hero to come to the same realization at the same pace. This is a solid quality HBO style movie and well worth your time.