Chip Bennett, the foreman of J. G. Whitmore's Flying U ranch, is sent to the railroad station to escort Margaret Whitmore, the boss's sister, to the Flying U. On their way to the ranch, Chip and Margaret narrowly escape a hold-up, which Margaret accuses Chip of staging for her benefit. In reality, Duncan, a neighboring rancher who is in league with foreign munitions runners, ordered the hold-up in an effort to drive the Whitmores from their land so that he can use an abandoned mine shack on the ranch to store munitions. To force the Whitmores from their land, Duncan orders his men to rob the bank so that J. G. will be unable to meet his payroll and thus be unable to repay his bank loan. As Duncan plots the takeover of the Flying U, Chip, infuriated by Margaret's accusations, quits his job and visits the town bank just as Duncan's men stage the robbery. Because he was present during the stick-up, Chip is suspected of being in league with the bandits, a suspicion that seems confirmed after he finds the payroll money hidden in the shack. When Margaret accuses Chip of being one of the bank robbers, he turns the payroll over to her and she locks it in the ranch safe. Chip then returns to the shack with ranch hands Dusty and Weary to await the return of the robbers. Chip's hunch pays off as they capture the outlaws and Chip recognizes them as Duncan's men. Chip takes his prisoners to the Flying U, where Duncan pulls his gun and demands the payroll money from the safe. Margaret, however, cleverly switched the payroll bag with her medical bag, and so Duncan and his men ride off with a satchel full of medication. As Chip and the sheriff ride after the bandits, Duncan returns and kidnaps Margaret and ties up Weary. After Duncan rides off, Weary frees himself and sends the posse to the shack in pursuit of the gun runners, while Chip rides after Margaret and Duncan. In the ensuing gun battle, Weary blows the foreign agents to bits when his well-aimed shot hits the explosives. Chip then overpowers Duncan and his gang and brings them to justice.