The young Mormon's father is a beloved and faithful man. This young man becomes a look-out for his community, locating and assisting in the attack of wagon trains to secure new wives for polygamists. One day, he observes a lone wagon train crossing the prairie. He discovers it is a young woman that he falls in love with at first sight. This love leads him to give up his faith and warn the emigrants. He joins in the fight against his own people and they defend themselves with the flag of truth. After his father learns of his son's apostasy, he sadly returns home. The emigrants are killed, the young Mormon takes the place of the emigrant, and together with the girl, they turn to a new life.