In the early days of the West it was customary for the Mormons to attack wagon trains, in order to secure new wives in the practice of their polygamous belief. The young son of the Mormon elder was dearly beloved and faithful and was given the post of outlook, to locate wagon trains, ascertain the number of men and women in them and assist in the attack. One morning he spies through his powerful telescope a lone wagon crossing the prairie. He hastens to a council of the elders and tells them of the approaching emigrants. He is sent to ascertain the number of men with the wagon and encounters the girl. It is a case of love at first sight. He gazes earnestly in the girl's eyes and sees an answering light in their depths. Then he realizes his mission and that the capture of these women will make them the wives of the prophet. A fierce desire overcomes him to possess her for himself, a thing not possible in the church. He renounces his faith and warns the emigrants. He assists in fighting off his own people and at last they hold up the flag of truth. The old father learns that his son has become an apostate. Sadly he returns to his home to grieve over his erring son lost to him forever. The emigrant having been killed, the young Mormon takes his place, and with the girl by his side turns to a new life with the woman he loves.