A stormy night brings a strange assortment of people to the deserted Sally Ann mine. Joe Ryan and his gang wait inside a shack, watched in secret by a pair of hidden eyes. John Mason, whose father left him a half-interest in the mine, rides into town with his sidekick, Clarence Washington Brown, just in time to stop a fight between Ryan and Benedict, the former manager of the mine, who implies that Ryan came by his half-share in the mine illegally. Benedict takes John and Clarence home with him where they meet Janet Carter, the daughter of Bill Carter, who discovered the mine with John's father. After a night of mysterious, ghostly comings and goings accompanied by flashing lights, Janet learns that Ryan's father framed her father in order to steal his interest in the mine. Carter, however, managed to hide the gold before he was taken to jail. When John hears her story, he offers to help her get Ryan. He arranges for Ryan to rob Clarence and then offers to trade Ryan's mine deed in exchange for not prosecuting him for robbery. Ryan's gang thwarts John's efforts by kidnapping him and later, Janet and Benedict, holding them in the mine shafts that run under the Carter house. A hooded figure, who turns out to be Carter, tries to rescue them and fails. After Clarence inadvertently scares Ryan's men, John escapes and sends his horse "Duke" home to round up his men. Ryan's men torture Carter until he reveals where he has hidden his gold. They load it into a cart, but before they can escape, John's men arrive and overcome the gang. Now that the gold is safe, John and Janet make plans for their future.