Five time-lost warriors -- a gladiator, a knight, a Babylonian, a cave man, and a viking -- appear in a small town near Challenger Mountain. The Challs battle and subdue the warriors, bringing them back to Challenger Mountain. J’Kal, an alien, who scoops up people from different times and places for his private zoo with the aid of his monster, Monstus, bursts into the headquarters and snare everyone. The Challs are trying to escape when J’Kal and Monstus are nabbed by an alien lawman, who promises to also return the warriors to their own time.; When the Challengers go hunting for two lost explorers, Hinton and Jarvis, they find the two men staggering from the jungle demanding gold for Xechulan. They grab gold artifacts - including a sacred shield - and disappear in red smoke. The Challengers split up and look for the men, but when Ace and Rocky find them, Hinton and Jarvis don't remember anything. Hatching a plot, Red and Prof later appear turned into gold from head to toe also demanding gold for Xechulan. But it is a ruse to expose Hinton's and Jarvis's false "possession" story and to return the gold shield to its rightful owners.