Lucky Rawlins, the foreman of the Bar W ranch, is returning from a cattle drive with a check for $12,000, the proceeds from the sale of the Bar W cattle. Posing as a new hand at the Bar W, outlaw Duke Cudlow rides to the trail camp and informs Lucky that Rance Williams, the owner of the Bar W, has been injured in a fall from his horse and needs his foreman to immediately return to the ranch. After Lucky and Duke leave for the ranch, cowhands Cannonball and Bob, suspicious of Duke's story, follow them. When Lucky arrives at the Bar W, he is greeted by several armed thugs, who demand the check from Lucky and then force Rance to endorse it. Soon after the outlaws gallop away with the check, Cannonball and the boys reach the ranch, and led by Lucky, pursue the thieves. Although the rest of the gang escapes, Lucky captures Slade, one of the outlaws. Soon after, Cash Watson, the owner of the bank and mastermind behind the plot to steal Rance's money and foreclose on his ranch, learns that Slade has been captured. After delivering Slade to jail, Lucky, who suspects that Watson is behind the robbery, discovers that the banker has already cashed the check made out to Rance. When Rance requests an extension on his bank loan, Watson refuses and threatens to foreclose on the Bar W. As Rance leaves Watson's office, he is approached by Bert Saunders, the bank manager, who offers to lend him the money to pay off his loan. Rance gratefully accepts his offer and arranges to meet Saunders and complete the deal at the big dance that night. Knowing that he must stop the loan and free Slade from jail before he talks, Watson tells Duke that he plans to kill Saunders at the dance and frame Rance for the murder. Watson then instructs Duke to break Slade out of jail when he hears the sound of the gunshots. At the party that night, the sheriff, sensing trouble, collects everyone's guns at the door. When Lucky learns from bank teller Judy Ware that the railroad wants to build a line across the Bar W, he deduces Watson's motive for forcing Rance into foreclosure. As Saunders and Rance retire outside to conclude their business, Watson slips the gun out of Rance's holster and shoots Saunders. Alerted by the sound of the gunshot, the crowd rushes outside and finds Rance standing over Saunders' body, holding the gun in one hand and money in the other. Soon after the sheriff arrests the rancher for murder, gunshots are heard coming from the jail, and Lucky forms a posse to pursue Slade and the others. After losing their prey in the darkness, Lucky and the boys return to town. There, Lucky discovers that Watson is turning the town against Rance and convinces the sheriff to free the rancher into his custody. When Watson learns that a cattle buyer is coming to buy Rance's herd, he orders one of his thugs to pose as a cattle inspector and quarantine the herd. Suspicious when the "inspector" is unable to produce his credentials, Lucky decides to set a trap for Watson. At the saloon, Lucky, Cannonball and Bob loudly discuss the arrival of the state veterinarian on the morning stage. The next morning, Lucky and the boys, all in disguise, pose as passengers on the stage. When Watson's men ambush the stage to eliminate the vet, they are greeted by the guns of the Bar W. Lucky and the boys then capture all but two of the outlaws, who ride to warn Watson. As Lucky and the others arrive in town, they see Watson fleeing out the back door of the bank. Lucky pursues and captures the banker, and some time later, Rance successfully closes his deal with the railroad.
