Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis]; captive aliens; Tartan the Ringmaster; the Stupendous Interplanetary Circus
The Challengers answer a shipwreck distress call, but find it's a mirage and a trap. They're pulled through space on a light beam and made captives of a rocket ship space circus. The heroes are prodded through cages and catapulted into a tank to fight Quadro, the Four-Finned Demons. Other alien performers are also captives. Ace coordinates an attack. Round cannonball-men fired from catapults pelt the guards while flying-men swoop on them. The Challengers battle and some captives escape. The heroes gain the cockpit and pilot the rocket to an asteroid made of glittering diamonds. As the Challengers prepare for a last stand, Prof learns the atmosphere gives them super-strength. They bombard the circus guards with boulders and disable the ships. The alien audience is surprised to learn the circus owners are criminals, and promise to send all the captives home. Ace says, "That's one flight it'll be a pleasure to make!"
Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis]; June Robbins; Charles Agar; the Shong; residents of Forbidden Valley
Flying over the Pacific, June Robbins crash-lands on an uncharted island and finds an Aladdin's lamp in a cave. Lighting it makes fumes that overpower her... The Challengers pinpointed June's radio call and land on the island. They find a hidden valley and Shangri-La city. Men in robes attack and the Challengers fight back. But June appears (in a daze) and gestures. A magical torrent washes the Challengers away. June, shadowed by a creep in green, then turns Rocky and Red into stone, then un-stones them. The creep is Agar, a U.S. criminal shipwrecked here. He became second-in-command to the Shong, the shaman. He keeps June mesmerized with the magic lamp - and she's reviving now. Ace and Prof crash the room, free their friends, and battle guards for the lamp. Grabbing June and Agar, they run for the pass. Rocky and Ace pull bullets apart for the gunpowder. "The sorceress is on our side now!" June gestures, the gunpowder ignites, and the roar scares off the guards. The Challengers take off in their jet - and drop the magic lamp into the ocean.