Senor is a thoroughbred horse who has won many blue ribbons, but when he gets old, ranch owner Jim Hartwell orders one of his employees, Steve, to take the old horse into the foothills and shoot him. Hartwell's daughter Kitty loves old Senor and claims him for her personal property. Steve loves Kitty and refuses to shoot the horse. In anger, Hartwell discharges him. The ranch owner, mounting his horse, leads Senor to the foothills. He takes the bit of blue ribbon which Kitty had tied in Senor's foretop, and throws it aside. Just as he raises his revolver to shoot, he sees a Mexican creeping towards his horse to steal him; he turns hi attention to the thief, who shoots him. Steve appears and fires at the Mexican, who shoots Steve and escapes. Steve, not seriously wounded, turns his attention to Mr. Hartwell. The Mexican makes his way afoot across the hills and comes across a party of range riders. He notifies them that Hartwell is dead and that he saw Steve shoot him. Steve is found bending over Hartwell. Hartwell is taken back to his ranch and Steve is delivered to the sheriff. Hartwell regains consciousness, but has lost all recollection of what has happened. Kitty tries in vain to make him recall the incidents of the shooting. He suddenly catches sight of Senor and immediately regains his memory and declares Steve's innocence and the Mexican's guilt. Kitty has learned that the sheriff and the ranchmen are about to hang Steve for the crime. She rushes from the house, mounts old Senor, and rides wildly to Steve's rescue. On her way she is intercepted by the Mexican, who throws her off Senor, then jumps on his back to make his escape in the opposite direction. She hastens on foot to stay Jim's execution and reaches there just in time to save him. Steve is released and the men hastily go in pursuit of the Mexican, whom they capture and condemn to death. Confronted with the evidence of his guilt, the bit of blue ribbon, which he had picked up when he shot Hartwell and dropped when he stopped Kitty on her way to Steve's rescue, he confesses and is sentenced to death.