 Xantos is the leader of a student counter-revolution that opposes violence, and is held in a prison by the United States army just across the border in Yuma, after he tried to find funding from the US and did not agree to give the monopoly of his country's entire oil wealth in return.El Vasco dislikes the suit-wearing Peterson and calls him a "penguin", but at the suggestion of General Mongo, the two reluctantly join forces and set out to capture Xantos.Their task is made harder by the American army and a wooden-armed American named John (Palance), who wants to exact revenge on Peterson, his former business partner.