'Steeley' Delaroy and his comrades accept the task of re-organizing the Air Force of Carabonia, a small republic in Central America, full of spies and rebels. They arrive to find a minor revolution in progress, everything derelict and in a state of utter chaos. A plane force-lands in the surrounding jungle after shooting-up the aerodrome and is found to be flown by the daughter of the deposed president, whose son is a prisoner of the rebels. From this girl our three friends learn the full story behind the revolution and decide to assist in the overthrow of the renegade president.