In their search for a wealthy man's long-lost son, private detectives arrive in North Fork. Upon seeing Mark, they decide that since they can't find the real boy and their client has never actually seen his son, Mark will suffice.
Stablehand Colly Vane, while out hunting, gets the drop on notorious wanted gunfighter The Domino Kid, and is forced to shoot him. When Colly brings the Kid's body into town to claim the reward, it's noticed that the Kid had been shot in the back. Instead of being hailed as a hero, Colly becomes the object of the townspeoples' derision for having shot the Kid in the back, is fired from his job and evicted from his house. To make matters worse, three gunfighters who were the Kid's friends come to town looking for him, and when they find out he's dead, set out to find ...
While North Fork excitedly awaits the arrival of a new preacher, Mark uncovers evidence that suggests the new parson is not only not a preacher, but may in face be planning to use the occasion to rob the town bank.
Marge Crandell is a headstrong young girl who doesn't like to be told what to do, not by her father or by Doug Carter, the man who loves her. Doug is hot tempered and ready to fight any man who gets too close to Marge. He has just such a fight with Fred Tate who had been bothering Marge. Instead of being grateful Marge walks off with the drummer Rodney Quentin. Later when Lucas discovers her body both Quentin and Tate emerge as possible suspects.
Gabe Fenway, a sharecropper for local landlord Preston, plans to run his quarterhorse Sapphire in a local horse race. Mark also plans to race his horse, Blueboy, in the race. Preston, who wants to keep all of Fenway's crops, believes Mark's horse can beat Fenway's and tricks Fenway into betting his crop against Preston's $1000 that Mark will win. And to make sure that Mark wins, Preston has a plan to make sure that Fenway doesn't make it to the race.
Lucas hires a new ranch hand, then learns that the man had just been released from prison for manslaughter. He believes the man has turned over a new leaf and wants to start a new life, but his--and the townspeoples'--suspicions are aroused when a local rancher is murdered during a robbery.
While in town one day, Lucas runs into Tom Benton, an old friend from his days in the army. Benton seems to have fallen on hard times, though, as he's drinking heavily and winds up shooting up the saloon and getting arrested by Micah. Lucas bails him out, against Benton's protests, but it turns out that Benton has his own reasons for wanting to stay in jail.
Nora Sanford, an old flame of Lucas' who came from a wealthy family, arrives in town, ill and penniless. When Lucas hears of her condition, he goes to see her and help nurse her back to health. It turns out that her recently deceased husband had spent all her money, and she had heard that Lucas had also been recently widowed, and in desperation decided to come to North Fork to see him. What Lucas doesn't know, however, is that she didn't come to town alone, and her plans for Lucas aren't quite what he thinks they are.
Lucas and Mark interrupt two young men stealing horses. Lucas is forced to defend himself and shoots and kills one of the men. He is one of Ma Boyle's sons. The Boyles are a mountain family who live by their own laws and Micah foresees trouble. When the clan arrives in town they are set on hanging the man responsible for the killing.
In Micah's absence, Lucas is forced into a duel to determine to which system of justice the blatant murder of a rural Hispanic resident applies: the old justice of traditional New Mexico Hispanics, administered by "Baranca", or the US law.
Milly Scott buys Hattie's general store. Her background as a schoolteacher does little to prepare her for what she bought into when she hires a stranger in town to collect all the debts owed to the store.
According to the stipulations in a bizarre will, the citizens of North Fork will divide $100,000 if Lucas McCain dies within seven days of Sarah Caruthers. The vicious old woman has hated Lucas ever since he killed her husband during a robbery.
Heading home on a stagecoach, Mark and Lucas are entertained by a little old lady's stories of gunslingers and her scrapbook of wanted posters. Little do they know she's a bounty hunter with her sights set on Duke Jennings, who's headed to Northfork.