The Commissioner of police at Marseille was unable to furnish Ace Williams with definite information concerning the headquarters of The Tunis Terror. However, he arranged with a seaplane pilot, Lieutenant Tamway, to fly Ace to Valencia, where they can interview Juan Carlos Domingo, who is refuted to know more about the terror than any other man in Europe. We find them now, flying high above the Mediterranean Sea on a south westerly course towards the coast of Spain...