An outlaw gang plans to take over and loot the town of North Fork by getting rid of the one man who could stand in their way: Lucas McCain.

The three Malakie boys comes to town and bust up the saloon. Lucas McCain and Marshal Micah Torrance stop them, but in the course of doing so, one of the boys shoots and kills his own brother. That doesn't stop them from blaming Lucas however and when their father Daniel Malakie arrives, he breaks his two surviving sons out of jail intent on getting even. They ambush someone they think is Lucas but get it wrong and Lucas and Micah hunt them down.

Al Walker, a notorious gunfighter, has come to North Fork to die. He has an incurable illness and, since he had once been a wealthy and prominent lawyer, believes he owes it to his family to have his death certificate read "natural causes" instead of "killed in gunfight". However, the Porter brothers--a gang of vicious killers and bank robbers--have followed him to town and plan to take their revenge on Walker for killing their brother, and they'll stop at nothing and no one in order to do it.

A newspaper article extolling Lucas' skills with a gun brings him trouble when a gunfighter shows up in town aiming to prove that he's faster than Lucas.

A recently widowed woman in North Fork doesn't know about her deceased husband's criminal past, and Lucas is determined to see that she doesn't find out.

When two outlaws threaten the life of Lil Halstead, daughter of the town's hotel clerk, Lucas sets out to determine the reason behind the threats.

Town ne'er-do-well Brett Conway finds out that a couple who moved near North Fork and soon fell sick are actually ill with highly contagious and potentially fatal yellow fever. Knowing that Lucas was the person who initially discovered the couple, Conway threatens to spread the news of their condition to the entire town, thereby causing a panic, unless Lucas buys his silence.

Lucas and Mark find themselves in deep trouble when their wagon breaks down while they're crossing the desert.

In order to rob the stage which is carrying $20,000.00 in cash, an unarmed outlaw informs Lucas, who is riding shotgun, that his son's life is in mortal danger if he doesn't hand over the money.

An outlaw gang kidnaps Micah and threatens to kill him unless their leader is released from jail. Lucas must decide whether to turn loose the notorious killer or face the possibility of the murder of his friend Micah.

Lucas tries to do a good turn for the town drunk, but things go awry when the man's son mistakenly believes that he is now the owner of Lucas' ranch.

A singer in a dance hall asks Lucas to take care of her daughter in order to hide the child from the woman's ex-husband, who has come to North Fork to take her away.

A young man who is hounded by fear of other people moves to the West, hoping the experience will toughen him up.

Mark tells Lucas that he overheard a plot to rob North Fork's bank. When Lucas questions him more closely about it, Mark, thinking that his father doesn't believe him, runs away from home.

A famous old frontiersman, with a reputation as the best rifleman around, challenges Luke to see who's really the best with a rifle.

A "mail-order husband" arrives in North Fork, and finds not only a bride, but also harassment from two local trouble-makers.

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.

Lucas finds himself attracted to a young widow who stops in North Fork on her way to claim an inheritance.

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 and kill the man who did it.

Lucas and Mark try to help out a man who has been swindled in a horse-trading transaction.

An older couple settles down in North Fork, but they have a secret--they're not using their real names because they don't want anyone to know that their son is a notorious gunfighter and killer.

A young boy and his sister, victims of an abusive father, come to the conclusion that the only way to protect themselves from further abuse is to kill him.

While on a train trip, Lucas and Mark are threatened by an escaped murderer. As if that weren't bad enough, the train is suddenly caught in a huge cloud of grasshoppers, forcing it to stop.

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.

Lucas sets out to save the life of a young soldier who has deserted from the army and is now scheduled to be executed.

Lucas is worried when Mark comes down with typhoid, but he gets even more worried when he notices that Mark doesn't appear to want to get better.

Lariat Jones, an old friend of Lucas', comes to North Fork to open up a casino. However, after several cheaters are caught in his casino, Lucas has to save his friend from almost certain death.

When a young headstrong woman is found murdered, a bit of Mark's mischief leads to the investigation down an apparent wrong path.

An ex-convict with a grudge against Lucas comes to town determined to kill him.

A man and his young son fleeing danger are taken in by Lucas. What Lucas doesn't know is that the man hasn't told him the real reason they're on the run.

A fleeing bank robber decides that the McCain ranch is a good place to hide out, so he holds Lucas and Mark prisoner in their own home until the heat dies down.

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.

A friend of Lucas is found murdered and robbed. Suspicion falls on an ex-con, and a lynching seems inevitable.