A bandit known as The Black Mask is terrorizing the countryside around the California border town of Caliboro. When word spreads that the Mask's gang is going to hit town, the town priest turns over the church's money to the local sheriff for safekeeping. The gang attacks the town and tries to take the money, but Deputy Phil Morgan stops it. Unfortunately, the sheriff is killed in the process. Morgan disguises himself as the Black Mask in order to find the gang's hideout, but is captured by the local townspeople who think he is the real Black Mask. Complications ensue.