When Lucas, Mark, and Micah get lost in Old Mexico, they are held hostage by a bunch of bandits who intend to kill the men and make Mark a slave. Micah is seriously hurt and buried alive - so it is all up to Lucas to save them.
Lucas arrives in North Fork to learn that a new arrival, Lou Mallory, has been been buying up land and some of the town's businesses. Mallory is a no-nonsense businesswoman, a self-starter who seems quite determined in looking after her own interests. Lucas even manages to get a very good price for Milly Scott's store, now that she's moved away. When the townsfolk learn that the railroad will be coming to town, several think they've been had, including Neb Jackman and his sons who sold her what they thought was a worthless piece of land. Neb's solution is to kidnap ...
Dennis O'Flarrety arrives in North Fork. Upon seeing an opportunity to help, he single-handedly lifts part of a wagon. But, his real reason for being in town is that he intends to marry Lou Mallory, the owner of the hotel.
North Fork is eagerly awaiting a visit from a U.S. Senator who is promoting Statehood for the territory. Micah has received a telegram saying there might be an attempt on the Senator's life but isn't too worried since a troop of soldiers are in town and have just checked in at the hotel. Oddly, the soldiers arrived with a large coffin-like box which they've taken up to their room. Lucas finds one of the soldier's behavior to be quite odd and with good reason: they are the assassins out to kill the Senator and the mysterious box contains a Gatling gun.
Mark and Lucas disagree on the character of a man claiming to work for the circus. Lucas shoots the man during a robbery at the hotel, but Mark believes the man's story. This puts father and son at odds.
A famous gun fighter, whom Mark idolizes, is in town telling more of his stories. But this time, he tells one story too many and is challenged. Lucas begins thinking that maybe he's not "the most amazing man" after all.
When Mark's careless actions cause the death of a friend, he blames the rifle. Not being able to accept the truth, he runs away from home. But he is faced with a tough decision that could be a matter of life and death.
Micah goes out of town, leaving Nils Swenson in charge. Lucas warns Nils against posting a "no gun" notice, and then angrily leaves town. He quickly returns, though, when he discovers Mark is in trouble because Nils didn't take Lucas's advice.
After Lucas barely misses killing a cougar threatening Mark, he goes into conflict with himself. The fact that his missing the cougar could have cost Mark his life terrifies him. Lucas must come to terms with this reality.
A murder occurs in the railroad camp near North Fork. The accused is found in the McCain barn where Mark and Lou hid him. As a result, when Lucas goes to the trial he finds himself being tried with the accused.
Lucas shot and killed a man years ago. Now, his son - who is Mark's age - is in North Fork for revenge. After he threatens a gunfight with Mark, Lucas demands him arrested and charged, but Lou Mallory has other plans.
It's a big day for North Fork - the first railroad train is coming to their new station. Riding as passengers are the McCains and a Japanese nobleman and his servant who are visiting the West to learn more about the United States. When the foreigners are insulted by a pair of local hooligans, they demand satisfaction, and soon the four men face off in North Fork's dusty main street.
On Halloween night Mark and his friends, wearing masks, ride from ranch to ranch playing pranks. A couple of rustlers hit on the idea of wearing similar masks while stealing cattle, knowing the boys will be blamed. They hide the animals in a gullible Englishman's barn, waiting for a chance to drive the herd across the Mexican border.
After running into Micah on the trail, Mark and Lucas stay to help him when the prisoner he is transporting injures Micah's arm. But the morning yields a serious problem. Lucas's life is in mortal danger and only the prisoner can save him.
Mark falls off his horse and becomes paralyzed. Doc Burrage confirms to Lucas that a visit to a hot spring may help. The only one near is a few days ride in the mountains and Lou offers to help. When they arrive they have to deal with the cold as well as three escaped convicts. To avoid discovery they have to hide which keeps them from lighting a fire. As it is getting cold, Lucas is forced to deal with the situation and confronts the convicts to save the day and his son.
It seems to be the end of the line for the Jackman clan after their farm is put up for sale to pay back taxes. It's clear they weren't cut out for farming and go off to Paradise, a nearby town. They arrive to find that the position of town Marshal is vacant and family patriarch Nebeneezert takes the job and deputizes his three sons. They soon realize just what they've got themselves into when they see that all of the badges have bullet holes in them. When bank robbers come to town, Lucas helps them keep the peace.
Mark and his girlfriend, Lorrie, become entangled in a feud between two old codgers. The teenagers soon learn that the "Hermit" has a bark that's worse than his bite when the old man invites them to lunch and allows them to look for arrowheads on a remote part of his land. The youngsters face dire peril when they become trapped in a pool of quicksand.