Frederick Kyle (Cameron Mitchell,) a distinguished gentleman with only one arm, arrives in Virginia City. Checking into the hotel, he asks the clerk if he knows the Cartwrights. Tom (Dan Riss) says everyone on the Washoe knows the Cartwrights and indicates that Adam and Little Joe are in town. Kyle asks if "Little Joe" is Joseph Francis. Tom laughs, "You call him that, you better be ready to duck."
Joe is in the adjoining saloon playing poker when Kyle comes in and watches. Joe doesn't realize it, but the man he's playing against, Gorman (John Anderson), is cheating. Gorman's partner, Regis (Stacy Harris) is standing behind Joe signalling. Kyle intervenes and manages to keep Joe from fighting the two. However, Regis pulls a gun and Gorman swings at Kyle. Despite his lack of one arm, Kyle fights a good fight and wins. Joe, meanwhile, has taken care of Regis. When the fights over, Joe asks Kyle to dinner. After they've left, Gorman wants to follow, but Regis says he remembers Kyle from Kansas. He figures Kyle will be their "money tree."
At dinner, Kyle says he's come to the area looking for silver investors for his backers in the East. Joe volunteers to introduce him to the silver mine owners. Hoss jokes that Kyle picked the wrong Cartwright. Joe has hot southern blood and doesn't understand hard cold cash. But Adam's from New England and it just comes naturally to him. Kyle asks about Hoss and he says he's in between. Ben explains that Hoss was born on the prairie as they came west. Hoss adds that he doesn't understand all this talk about North and South. Ben assures him that they all have roots on the Ponderosa now. Kyle says that ideologies go deeper than where a person lives, but changes the subject by accepting Joe's offer to meet the silver owners.
The next day in the saloon, Hoss and Ben walk into an argument about North and South. Again, Ben tries to calm things by saying Virginia City is neither. The Yankee (Mickey Simpson) notices Ben has a NY newspaper and asks Ben what it says. The Reb (John Locke) doesn't want to hear a northern's view, but Ben is encouraged to read it. Ben reads about Lincoln's "House Divided" speech. The argument begins to flare up again, but Kyle has entered the saloon and he has a newspaper from Charleston. He too reads about the speech, but it's not entirely condemning. Yank is surprised a southern paper would write that. Kyle replies, "A man who honestly knows what he believes and has courage enough to act on it, is a man deserving of praise from all men."
Returning to his hotel room, Kyle is stopped by Regis and Gorman. They've been checking into Kyle and know he's there to acquire silver ore. They figure it's for "the Cause." Regis says there are some owners who might not want to go along and for $5000, he and Gorman can be Kyle's own little army. Kyle listens, but is infuriated at their reference "for the Cause." Shoving Regis against the wall, he threatens them not to speak of the Cause that way. Again, Gorman wants to fight, but Regis stops him and says this is just a business arrangement. Kyle agrees to that.
Adam goes to the hotel looking for Joe. Tom tells him that Joe had been out introducing Kyle around, but now Kyle's upstairs alone. Just then, Regis and Gorman come down talking about the temper of the one armed man. Adam wonders who they are and why they're talking to Kyle. Tom says the two just got out of prison, but he doesn't know anything about Kyle. If anyone knows about Kyle, it'd be Joe since they've spent so much time together lately. In fact, Tom mentions, Kyle asked about Joe as soon as he got into town.
Adam goes home and informs Ben about Kyle's interest in Joe. Ben's concerned and goes into town himself.
Kyle and Joe are meeting with mine owner, Hennessy (Howard Wendell) in the saloon. Hennessy is not interested in selling his ore to Kyle. Not only does he have buyers in San Francisco, but he wouldn't sell to Kyle anyway. He's heard about Kyle's Southern sympathies and his leanings are in the opposite direction. He leaves. Joe doesn't understand why Hennessy would bring politics into a business deal, especially since Kyle was offering 1/3 more for the ore. Kyle isn't concerned and thanks Joe for introducing him to so many mine owners. He says it helps to have a Cartwright on his side. Joe doesn't understand that and Kyle says before he came to Virginia City he did some research. He checked to see if the Cartwrights were the same ones he'd heard about. He tells Joe that he knew Joe's mother, Marie in New Orleans. He gives Joe a pocket portrait of Marie that he's had for years. Joe is very moved with the gift. To cover his emotions, he offers to take Kyle to meet the last few mine owners in the morning and leaves.
Ben enters the hotel and asks Tom about Kyle. A woman happens to overhear and says she just checked Kyle's room and he's not in. She introduces herself as Lily Van Cleet (Marianne Stewart) who's on her way to California. They sit in the adjoining restaurant and chat. She learns that Ben has a ranch and three sons. She says she had a son named Joseph too. But he died a year ago in a street fight. "What's happening in Virginia City happened in the east over a year ago." She lost her son and her husband that night.
Kyle walks up and is surprised to see Lily. Before he can walk her away, Ben asks to speak to him. She gives them a chance to speak privately and Ben wants to know why Kyle sought Joe out. Kyle admits that he knew Marie and gave Joe a picture of her. Ben warns Kyle to leave Joe alone.
The next morning, in Kyle's room, Lily combs her hair. They're married, but she's the daughter of a Northern senator and doesn't believe in her husband's cause. But she does still love him. She laments that this cause has taken their son, his arm, and their marriage. He's still angry that Northern hypocrites took their son, but promises to return to her when all this is over.
Later, Hennessy tells Kyle that he's going to Washington and he's going to tell people what Kyle is up to. Kyle threatens him not to try it. When Hennessy leaves, Kyle calls Regis over.
Hennessy and Lily both climb aboard the stage. As it moves through a mountain turn, it suddenly falls over a cliff.
The bodies have been brought to the Ponderosa and seeing who the victims were, Ben has contacted Kyle. Kyle looks under the blanket and cringes. He asks how it happened. A boulder was in the middle of the road and the driver didn't have a chance. Based on the foot prints, two men were involved. Ben asks who the woman was to Kyle. Kyle merely says she was someone he once knew. Adam is frustrated and demands to know what Kyle is planning. Joe defends Kyle, but Adam insists Kyle is hiding something. Ben breaks it up.
Kyle returns to the saloon and finds Gorman and Regis. At gunpoint, he takes them into a small supply room at the back. He tosses the gun aside and proceeds to beat both of them up.
The next day at the crash site, Kyle finds Lily's cape and caresses it. The sheriff (Kenneth MacDonald) agrees it was murder, but wants to know why Kyle thought Regis and Gorman were involved. Hoss and Joe come down with some tools and one has Gorman's initials on it. That may prove it was Regis and Gorman, but Adam too wants to know how Kyle knew that last night when he beat the two up. Again, Joe comes to Kyle's defense saying Adam's had it out for Kyle since he arrived. They start to fight, but Ben breaks it up. "Brother against brother. How dare you! Each of you."
Ben has dozed off when Hoss and Adam wake him to say the Joe came home, but backed a bag and left again. Ben wants to know why Adam didn't stop him. Feeling a bit guilty, Adam says he intends to and walks out. Hoss tells Ben that Adam plans to leave too. Ben hurries after him.
He tries to stop Adam, who's gathering his things, but Adam won't listen. He says he's going to New England, but wants Joe to know that suddenly he found himself saying things he didn't mean, didn't even believe. Then marches over to his waiting horse. Ben again tries to plead with Adam to stay. He can't stand by and watch his family fall apart. Adam tells him the damage has already been done. "It's got to be me or Little Joe and he needs you more than I do." Ben is very worried and begs Adam, "I don't want you to go." Adam doesn't want to leave, but says they can't have two different views in the same house, it won't work! And he rides off. Hoss figures that Mr. Lincoln must've been talking about houses like theirs. "No, not us, Hoss. Not us," Ben quietly insists.
Kyle and Joe are meeting with some of the mine owners when Ben barges in and kicks them all out. He says Joe can stay and hear what he has to say and then Joe can decide for himself what he wants to do. Ben accuses Kyle of acquiring the silver to back the Confederacy. He accuses Kyle of giving anything for his beliefs. Kyle doesn't see anything wrong with that, or doesn't Ben believe in anything? "I believe in my sons," Ben says firmly. And he lost two of them today. Joe feels a bit ashamed about that. Ben again asks about Lily. Kyle refuses to talk about her. Ben says he knows, he could feel, that Kyle loved her. What is Kyle willing to sacrifice? Kyle still won't answer, though he's clearly bothered by Ben's talk. Ben asks if she was just a woman he met in a saloon? This pushes Kyle over the edge and he starts to attack Ben, but he can't swing. He complains that Ben wasn't going to get involved, this wasn't Ben's fight. Ben says Kyle made it his fight. He reminds Kyle that Kyle lost a son and now a wife, will nothing stand in his way. Kyle says nothing will. And this won't be the end. There will be brother against brother and father against son. Ben tells him that in the end it will all have been a useless waste.
When Kyle leaves, Joe knows what he's lost and apologizes to Ben. Ben reminds him that a tree has many roots, but it only has one tap root and Joe's is on the Ponderosa.
Joe has gone in search of Adam, only to find him staring out over the lake. Joe says he has something to say and Adam had better listen. He says Adam has always been the one who got to stay up late and other privileges because he was the oldest and helped Ben with the problems of the Ponderosa. Well Joe's not going to take it anymore, not if he and Hoss are the ones who are staying. Adam doesn't look at him, but continues to look at the lake. "That lake sure gets under your skin. Let's go home."