Because of his lack of brains, Clyde is sent out west by an irate step-father to accumulate some of that spirit that makes men of men. He arrives simultaneously with the arrival of the last of the Pony Express riders who is fatally wounded. Thirty miles of the journey of the valuable mail pouch have still to be covered. A volunteer is called for the dangerous mission. Cook is reluctantly impressed into the service. He accomplishes the mission after some wild experiences with Indians, bears and other obstacles.