Kate Diamond, the owner of a prosperous general store, is also the boss of a gang that smuggles guns to the local Indians. However, when she short-changes supplier Stacey, her henchman, Nebraska, warns her that Stacey may retaliate. He does by recovering his shipment of guns, which were hidden in a mine, and sending three men riding after Nebraska. The gun shots alert passing riders Jimmy Wakely and "Cannonball" who come to Nebraska's aid. After Nebraska shoots and kills one of his pursuers, he is relieved to find that his rescuers are old friends who will vouch for his innocence. Jimmy and Cannonball proceed on their way into town to visit another old friend, Sheriff Ted Harris, and to file a homestead claim. After they leave, Harris shows up and arrests Nebraska, but he claims that he has witnesses. At the sheriff's office, Jimmy meets Ted's niece Jessica and later vouches for Nebraska who then is released. After Danny, a half-breed Indian, tells Kate that his chief almost went on the warpath when he discovered that the last guns she sold him were faulty, she gives him a sample rifle from a new shipment. However, when Ted stops Danny as he drives his buggy through town and discovers the rifle, Danny shoots him and drives off. Jimmy chases after Danny and captures him. While Ted is recovering, he asks Jimmy to look after Jessica and gives him an envelope and a document that proves that Nebraska is actually Jessica's father, but asks Jimmy that she never be told this. Kate overhears Ted's revelation, but Ted is not concerned as he regards her as an old friend. Ted explains that he and Nebraska were friends until Nebraska became a hired gun and took off for Mexico. Soon after, Nebraska's wife asked Ted on her deathbed to bring up Jessica and keep her parentage a secret. Later, Nebraska was told that Jessica had also died. After Ted convinces Jimmy to stay around and help his deputies, Jimmy suggests letting Danny escape so that he will lead them to the person selling the guns. Danny leads Jimmy, Cannonball and deputy Burt to the guns's storage place, and there they capture the gang members. Kate, meanwhile, instructs Nebraska to get rid of Jimmy, but instead he advises Jimmy to leave town, as he has heard a rumor that he could get hurt. When Danny visits Kate to complain about the non-delivery of the guns, Kate and Nebraska discover that he has been followed by Jimmy and Burt, prompting Kate to shoot and kill Danny, claiming that he was trying to rob her safe. Jimmy, suspicious of Kate and her involvement with Nebraska, decides to put up road blocks around the town and Indian reservation to stop guns from getting through. However, Kate persuades Jessica to take Ted to another doctor in a nearby town and arranges to transport him there in the regular freight wagon in which she conceals the gun shipment. When Jimmy hears about Ted's journey, he goes after the wagon, which passes easily through the road block. While the gang attacks the wagon, Nebraska draws his gun on Jimmy and refuses to let him continue. Concerned about Jessica's safety, Jimmy tells Nebraska that she is his daughter and that Kate has known this for sometime. Nebraska joins forces with Jimmy and gets the drop on Kate's men. When he orders them to stop firing on Ted and Jessica, Kate shoots him. As Jimmy and the others capture the gang, Kate tries to finish off Nebraska, but he shoots her. Jessica thanks Nebraska for helping them, and with his dying breath, Nebraska asks Jimmy to make sure that Jessica never learns the truth about their relationship. The survivors of Kate's gang receive long prison terms, and Jimmy and Cannonball move on to their next adventure.