Paladin stops at a general store at a town that he passes through, and listens as the owner, Jason Coldwell, jokes with Daniel Weaver and his son Joel. Daniel isn't amused and leaves, and Jason contemptuously dismisses him as an ignorant fool. Paladin buys his breakfast and some shells, just as the school bell rings. Becky, Jason's daughter, starts to leave but he glares at her and she goes back to darning a sock. Paladin wonders why she isn't going to school and Jason explains that the teacher, Mollie Stanton, is a troublemaker. A rancher, Jackson Breck, heard that Mollie was teaching that Quantrill and his raiders committed atrocities during the war. Breck rode with Quantrill and took offense, and told Mollie to retract her statement. She refuses and Breck threatened to burn down her school when he comes back from a cattle drive.
Paladin figures that Breck is the troublemaker and when Jason disagrees, draws on him. Jason quickly agrees and Paladin points out that it's a matter of historical fact that Quantrill did bloody work. When the owner disagrees, Paladin says that he doesn't like the number 2 so Mollie should stop teaching about it and anything else someone might object to. Jason sticks by his argument and Paladin asks for directions to the school. When Jason wonders if Breck hired him, a disgusted Paladin says that he wouldn't ride a thousand miles just to burn a schoolteacher out. As he leaves, Paladin compliments Becky on her darning.
When Paladin rides up to the school, Daniel's youngest son Morse is there, armed with a rifle. He explains that he has for Indians and rabbits. An amused Paladin follows the boy in and asks Mollie if they can talk alone. She leads him into her single room at the back of the school after giving her students their assignments. Once they're alone, Paladin tells her to stop teaching about the Union Jayhawkers and their atrocities. Mollie refuses, pointing out that there's another man that wants her to stop teaching about Quantrill's atrocities.
Impressed, Paladin explains that he wanted to confirm that she wasn't taking sides. Mollie wonders who he is and Paladin gives her his card. When he says that he's there to help her, Mollie breaks into tears and admits that she's alone because no one in town will stand up to Breck and his men. Paladin promises to be there for her and says that he'll stay there, and Mollie invites him to use her bed while she teaches.
As Mollie teaches the few students whose parents will let attend, Breck's man Coley barges in. When he confirms that she's still teaching about Quantrill, Coley knocks over her desk. Paladin comes out and orders him to clean up the mess, ushering the children out of the way. Coley tries to draw on Paladin, who shoots him in the arm and then forces him to pick up the desk. Once he leaves, Paladin asks Mollie to teach the students why he had to shoot another man. Mollie orders her students back to their desks and Morse smiles admiringly at Paladin.
That night, Paladin makes supper and Mollie figures that his cause is hopeless. Paladin asks her for a list of all of her students and their addresses. When Mollie warns him that the families won't help her, Paladin insists that teachers are a vital part of any civilization.
Paladin rides to the general store and tries to convince Jason, who is unimpressed. As Becky listens, Paladin warns Jason that his daughter will learn from what he does as well as what he says. Paladin then rides to the other families. His last stop is the Weaver ranch. Daniel invites him in and introduces the gunfighter to his sons Frank and Joel. Paladin tells Daniel why he's there but the rancher knows he hasn't found anyone to help. Paladin wonders why Daniel won't help and the rancher explains that Frank was shot at Gettysburg and Joel lost his arm at Chickamauga. He lost his farm to Sherman when he marched through their land, and doesn't see any difference between the North and the South.
Paladin turns to Morse and asks him if Mollie taught him about Sherman's March. The boy says that his teacher told them about both sides and the terrible things that they did. The gunfighter notes that a Union sympathizer could say the same thing that Breck is, but Daniel still insists that it's his fight. When he says that he'd fight if his neighbors did, and Paladin suggests that he should fight for himself and his family. Disgusted, Paladin tells Daniel that he's a coward but at least the other townspeople will admit it. A furious Daniel grabs Paladin and says that he can't insult him and walk away. Paladin knocks his hands away and tells him to meet him at the school the next day if he wants a fight.
The next day, Mollie rings the bell but no one comes, students or parents. Paladin assures Mollie that he'll fight, just as Becky runs up. She apologizes for missing the last two weeks of school and Mollie takes her in to make up for her missed lessons.
As Breck and his men ride through town, Jason hears them and realizes that Becky is gone. He grabs his gun and runs to the school.
Breck and his men approach the school, and find Paladin waiting for them. They easily attack and beat him to the ground, and Mollie runs out and tells them to leave Paladin alone. Jason runs over to protect Becky, and Breck takes the girl's book and lights it. He throws it on the porch and Becky stomps it out. When Breck goes after her, Jason aims his pistol at him.
As Breck and his men prepare to kill Jason and Paladin, Daniel and his sons ride up, wearing their Confederate uniforms. Daniel orders Breck to hand over Paladin, who says that he'll have to wait his turn. He then turns to Breck and dares him to shoot now that it's a fair fight. Breck wisely refuses to draw and Paladin slaps him, calling the rancher a coward. The gunfighter then turns to Coley and his men. They know better as well, and Daniel tells Joel to oblige Paladin. Realizing that he's lost, Breck contemptuously says that Mollie isn't worth it, calling her a homemade schoolteacher. Paladin threatens him until he apologizes for the remark. The gunfighter then tells Breck to let it end there. Much to his surprise, Daniel and Jason back Paladin up.
Once Breck leaves, Daniel reminds Paladin that there's the matter of the insult. Paladin figures that it's not true but says that Daniel was afraid that the townspeople would consider him a fool if he helped. Jason admits that Paladin is right, and Mollie orders Morse and Becky inside. Morse considers it a waste of time but Daniel tells him to go inside and learn how to be a better man than his father. As she turns to go, Mollie thanks Paladin and invites them to join her for dinner that night. Paladin thanks her, and Jason invites Paladin as well as Daniel and his family to stay with him until dinner. They accept and as Paladin rides off, Morse watches him admiringly from the schoolhouse. Molly notices the boy's hero worship and, smiling, keeps on teaching.