A mysterious "night rider" has been raiding ranches and robbing banks. When a stranger comes into town, Jeff Barton, owner of the saloon, recognizes his gunbelt and believes him to be the feared "Bad Jim Blake," but he is actually John Brown, an officer of the law. John is working with two sidekicks to capture the night rider: Altoony, an apparently elderly tourist, and Manuel Valdez, a hired hand working for Barbara Rogers' ranch. John is secretly in cahoots with the sheriff, who knows his true identity. Barton recommends John to Barbara as foreman of her ranch, so he can keep an eye on him. John intercepts gang messages and, using notes and a special seal, poses as their chief. After a bank robbery, John trails the robber to Barbara's house, but the robber eludes him. Upon hearing how Barbara's brother Dan was made an invalid by an explosion at their mine and their father was killed, John investigates the mine. He discovers a secret passage into the house. For appearance's sake, the sheriff arrests John, but allows him to escape. John fools Barton into believing he is head of the gang and plans another robbery. Manuel guards Tula, the housekeeper, but she knocks him out and tries to help Dan, who is not really an invalid but actually is the night rider, escape. The sheriff and a posse arrest Barton and his men at the mine, while John captures Dan. It is revealed that Altoony is Barbara's uncle, and John chooses to stay on as a foreman after revealing his true identity.