Pastor Holt of Arizona has a daughter, Ellen, and a son, John. John is inclined to be a trifle restless under the home discipline. The pastor gives John a sum of money to deposit in a bank at Grey Rock. This money is for the erection of a new mission. Ellen meanwhile has sold her horse, Jim, to complete the sum necessary for the erection of same. Bill Evers, a gambling house keeper, is in reality the "Desert Scourge," an outlaw. He buys the horse of Ellen from a trader, and while robbing the stage the horse breaks its tether and returns to the parsonage. John Holt arrives at Grey Rock and loses both the money and his watch at the gambling hall. The watch contains a picture of his sister, and Bill Evers is greatly smitten with the girl's appearance. He meets through an inquiry in the newspaper, stating that the horse has returned, Ellen Hold, and falls in love with her. She reciprocates his affection. John is sent to the bank where he says he deposited the money. While en route he attempts to rob the stage to recover the church money he lost in gambling. He is wounded and the horse carries him home. Bill Evers, who is engaged to marry Ellen, is calling at the house. The posse follows the boy by a trail of blood and Bill Evers makes the great sacrifice of taking the boy's place and announcing his identity. He is removed by the posse but escapes, and the story ends in the reunion of Ellen and Evers.