When Granny, an elderly fur trapper refuses to sell her property to a gang of outlaws, they try to get her land through legal means – by attempting to get her declared insane.

When a less than honest postmaster learns that a valuable bank shipment will be passing through Mineral City on the train, he hires a pair of gunmen to blast the train track in order to get his hands on the money. As a result, Roy gets deputized to help the sheriff out.