Bob Adams, returning from a visit to the East, brings his sister out to the Mexican border to his ranch. Mae is inclined to flirt. Bob is inclined to be jealous and discharges one of his hands for taking advantage of one of his sister’s flirtatious moods. Miss Mae, in attempting to chop some wood, strains her shoulder. The old foreman of the ranch tries to quiet her, but is discovered by Adams, who, in a fit of jealous rage, struggles over a revolver and accidentally shoots the foreman. He knows the penalty and decides to ride across the border into Mexico, where he becomes acquainted with Carmelita, Ramon’s sweetheart, and afterwards marries her. Ramon, with a broken heart, goes into the States and by one of those queer turns of nature, goes to the Adams’ ranch and applies for work. He becomes infatuated with Mae, Adams’ sister. After many months have passed, Carmelita finds Adams flirting with another Spanish girl, innocently enough, but jealousy overpowers reason and she takes her own life. Adams, being thoroughly frightened, recrosses into the States to seek protection against the just anger of the Mexicans, and there meets with Ramon, in his own home. Ramon, thinking that he is trying to steal Miss Adams, tells her that this is the man who took from him his love and defies him to attempt to use his art on Mae. A struggle ensues and Ramon mortally wounds Adams and takes to flight. The cowmen follow and drive him into an old hut, where they try to dislodge him by bullets, eventually using dynamite. Adams, in the meantime, regains consciousness sufficiently to get onto a horse and ride to Ramon’s rescue, but arrives only in time to shake his hand, and, both men die as they lived, victims of that grim monster, jealousy.