Republic, in pre-production trade announcements, had John Wayne slated as the star of this film but cooler heads, once the script was read, realized that Wayne wasn't exactly the dual-role, twin brothers type. The film opens by establishing that, as young boys, David Cook and twin brother Tom are poles apart in disposition and traits. When their father dies, Tom goes to New Mexico to live with his Uncle Hardtack while David remains behind to care for their mother. The grown Tom becomes an outlaw while brother David becomes a government lawman. David is charged with apprehending Tom and also two other renegades, Hardman and Marsden, both bitter enemies of Tom. Unable to arrest Tom in his home territory because he is in league with crooked sheriff McDaniels. Tom is lured home by a fake telegram telling him his mother is dying and put in jail. David, posing as Tom, goes to Mesa City, New Mexico and undertakes a campaign to obtain evidence to convict Hardman and Marsden.