What Cha-Ka believes is an animal crashing down from the sky Jack learns is actually a hot air balloon manned by American adventurist Colonel Roscoe T. Post, who was attempting what would have been the first successful hot air balloon crossing of the Andes... in 1920. Jack is able to convince him that in return for helping him fix his balloon that he take them with him back to Earth. Will is quietly nervous as he is uncertain as to their fate if they are transported back to 1920, an era when they would not yet have been born. That may be a moot point if the colonel has his way, as all he is really interested in is fame and fortune by his feats, despite being less than the brave adventurist he makes himself out to be. The fame in this case means exploiting Cha-Ka as a sideshow attraction as what he believes is the missing link. The colonel will sacrifice the Marshalls' wants for his own, which means leaving them behind and taking only Cha-Ka. Before any of them gets what they want, they will also have to battle the Sleestak, who believe the colonel is just another human intruder attempting to be God through his power, which they see as his flight through the balloon. Destroying the balloon means destroying his power.
—Huggo