Heading an aviation company that develops atom-powered motors, Jim Fairfield (Pierre Watkin) learns from his chief scientists, Vic Hardy (Hugh Prosser), that cosmic radiations are being employed for experiments at a point outside Aherica. This information is told to Jim's nephew Billy Fairfield (...

Jack Armstrong saves himself and his friends by forcing the plane into a a belly landing. Jason Grood (Charles Middleton), owner of the island's trading post and the brains behind the cosmic rays scheme, sends henchman Blair (Jack Ingram) to bring the Fairfield party to the trading post. Blair ki...

Jack and Betty are saved from the fiery pit by Umala (Russ Vincent), a native who now realizes that his enemies are the white men working for Grood. The latter orders his henchmen to shoot Jack and his friends on sight. Blair and his fellow henchmen combined with Princess Alura natives maneuver t...

Jack and his friends land on a rocky ledge and make their way to the ground below. Meanwhile, Grood plans a fantastic demonstration to impress the natives.An aeroglobe, able to go far beyond the earth's atmosphere, is sent aloft. From their hiding place, Jack, Betty, Uncle Jim, and Billy realize ...

As the aeroglobe settles in its berth, Jack and the Fairfields flatten themselves against the walls of the pit and escape death. Princess Alura, believing that Xalta is on the side of Jack and his friends because of their miraculous escapes, urges them to leave the island. Jack insists on rescuin...

Jack retains consciousness long enough to douse the poison gas bomb with sand, saving himself and Uncle Jim. Later, Pierce joins them, still pretending friendship, to look for Vic Hardy. They are trailed by Blair who, when questioned at length, gives them false directions to Hardy's location. Pie...

Betty reaches the well just in time to save Jack, Uncle Jim, and Billy. Uncle Jim then decides to confront Grood, now suspected to be the brains behind the terrible scheme, and intimates a knowledge of the secret caverns where experiments are in progress. Grood refuses to be drawn out. Bill then ...

Jack and Uncle Jim who have been trailing the truck are set upon by Grood's henchmen. The timely arrival of Umala and friendly natives saves the situation' Billy is rescued. Grood now plans to eliminate Umala and his followers for their aid to Jack and the Fairfields. He attempts to arouse the na...

The knives fly wild when two shots ring out. Uncle Jim arrived with Billy and Umala just in time. But they are surrounded by hostile natives After a fight between Umala and Naga (Frank Mario), Princess Alura's traitorous prime minister, with Umala victorious. the white men are freed, and Princess...

The beam is deflected when Jack and Billy attack and overpower the henchmen operating the Annihilator. Pierce and his men, now opposed to Grood, wrest the gun away from Jack, but they cannot operate the Annihilator gun without solarium, an important element needed for its operation. Grood and his...

Jack, unharmed by the fall, escapes his opponent, commandeers Grood's truck and rescues Uncle Jim and Billy. They cannot carry off the Beam Gun, but take the activator tube, an important part of the weapon. Pierce starts out for the underground laboratory to find a substitute for the activator. J...

The figure in the path of the death ray was Pierce and he was killed, Grood's henchmen capture Jack and Uncle Jim and take them to the laboratory. But Vic Hardy is there, and he knocks out the guard. Hardy remains behind, hoping to circumvent Grood's scheme for wold domination. Jack and Uncle Jim...

Struggling with one of the guards, Jack had fallen to the ground before the truck went over the cliff and destroyed the infamous Beam Gun. Grood learns from Zorn that a master Dosmic Beam Annihilator has been completed and and installed on the Aeroglobe. He plans to annihilate an entire city. Har...

Jack parachutes to safety as the Areoglobe explodes, killing Zorn and other Grood henchmen and destroying the master death machine. REgaining consciousness, Vic Hardy demands that Grood sign a full confession of his guilt. Jack, Uncle Jim, Billy, and Betty enter the secret laboratory just as Groo...