During the Civil War, Luke Cottrell and his guerrilla raiders plunder the area south of St. Louis, Missouri in the name of the Union army. Driven from their land, settlers filter into Texas. After Cottrell burns the Three Bell Ranch belonging to Kip Davis and his partners, Charlie Burns and Lee Price, the partners vow vengeance. Despite the entreaties of Kip's fiancée, Deborah Miller, to join her in the small town of Edenton, the partners head to the Texas border town of Brownsville to look for Cottrell. Once they reach Brownsville, Lee decides to join the Confederate army, and Kip and Charlie try to raise a stake to rebuild their ranch. Rouge de Lisle, a saloon singer, offers Kip fifty dollars to transport a wagon of furniture, but when the shipment turns out to be filled with firearms, Kip is arrested. On the way to the stockade, however, a sympathizer drops Kip on the road, where Rouge picks him up. She then proposes that he and Charlie join her in smuggling guns for the Confederacy from Matamoros, Mexico into Brownsville. When the trio reaches Matamoros, Rouge's accomplice, Henri Brugnon, informs them that he has sold all his guns to Cottrell. Meanwhile, Charlie hires a gang of men, including Slim Hansen, a former associate of Cottrell. Some months later, Kip and Charlie bring a load of guns into Texas and find Cottrell waiting for them on the other side of the border. A gunfight ensues, and Kip's men are rescued by a contingent of Confederate soldiers, including Lee. When Kip and the others arrive in Edenton, Deb again begs him to stay, but Kip is determined to make enough money to rebuild his ranch and continues to smuggle guns. After Brownsville is recaptured by the rebel forces, Kip wants to return to Three Bell. Lee, who is now a lieutenant in the army, chooses to continue fighting, and Charlie, who has become more interested in money than in ranching, decides to remain with the gunrunners. Kip then asks Deb to join him at the ranch, but she is working as a nurse, and does not want to leave her duties. Rouge, who has fallen in love with Kip, is relieved when he returns to smuggling. After Cottrell threatens to kill Kip and Charlie if they return to Matamoros, Slim suggests that they steal the shipment of arms before it reaches the Mexican city. Kip and his men dress up as Union soldiers and steal the guns, but later, meet a contingent of Confederate soldiers at the border. Mistaking them for the enemy, the rebels open fire and many soldiers are killed during the ensuing gunfight. Lee suspects the truth and ends his partnership with Kip and Charlie. Then Cottrell kills one of Kip's men, and Kip resolves to kill him. Slim warns Cottrell, hoping to eliminate Kip so that Charlie will become the leader of the gang. Kip avoids the ambush, but before Cottrell can tell him about Slim's doublecross, Slim kills him. Kip then returns to Edenton, where he learns that Deb has fallen in love with Lee. Having lost both of his friends and his fiancée, Kip leaves for Matamoros, accompanied by Rouge. After the war ends, Lee joins the newly established Texas Rangers. He is sent to Brownsville, where he is threatened by Charlie. Unknown to Lee, Deb rides to Matamoros to ask for Kip's help. With Rouge's encouragement, Kip rides to Lee's aid. At the last minute, Charlie joins his old friends, but the treacherous Slim shoots him. Before he dies, Kip promises Charlie that the ranch will always remain the Three Bell. Later, he marries Rouge and returns to rebuild the ranch.