A mysterious outlaw known as the Sidewinder, phantom leader of renegade Ute Indians, terrorizes the people of the Arizona Territory in the 1870s. When rancher Tex McCloud has his place burned out, he vows to find and kill the Sidewinder.
It's just after the Civil War and Ben Shelby arrives looking for Johnny Tallon whom he plans to kill. Shelby was the only survivor of a battle due to the cowardice of Tallon. Thinking Tallon dead, another man who lost a brother at the same battle arrives to kill Tallon's blind brother. Tallon arrives to find Shelby and his brother fleeing. Then they are attacked by Indians and Shelby and Tallon must now fight together postponing the inevitable showdown.
Dardo, a Robin Hood-like figure, and his loyal followers use a Roman ruin in Medieval Lombardy as their headquarters as they conduct an insurgency against their Hessian conquerors.