While going to the aid of a captive fellow scientist in the Amazon jungle, Dr. Quest is abducted (for ritual sacrifice) by a tribe of hostile native warriors.

Dr. Zin sends a large, black, cyclopean, four-legged spider-like robot (by a flying saucer-like craft) to a U.S. government research facility in the American Southwest to steal the secrets of a para-power ray gun on which Dr. Quest is working.

While researching marine biology in the Caribbean, Dr. Quest encounters a phony witch doctor, who is protecting a secret submarine base (under construction by a criminal contractor) with his supposed voodoo powers.

When the members of his team descend in a plane crash over uncharted jungle territory, Dr. Quest must rescue them (with the help of local authorities) from a tribe of hostile Pygmy warriors.

While searching for a rare strategic mineral in the Amazon jungle, Dr. Quest and Race discover a prehistoric Pteranodon, trained by a wheelchair-bound slave driver to capture and guard native workers needed for his mining operation.

While investigating unusual tremors on a tropical island in the South Pacific, Dr. Quest and Race uncover a secret ray gun base (operated by Dr. Zin and protected by hovercraft-mounted guards) hidden deep within a local volcano.

While hunting for samples of petrified wood in the Canadian Rockies, Dr. Quest is threatened by a gang of lumberjacks (one of whom disguises himself as a werewolf) intent on protecting their gold-smuggling operation.

Dr. Quest responds to the distress signal from a fellow scientist, who has accidentally unleashed an (invisible) energy monster on a South Pacific island.

While doing atmospheric research in the African savanna, Dr. Quest uncovers an inaccessibly high plateau, populated by prehistoric cavemen, who have been trained as slave laborers for diamond mining by Klaus Heinrich von Dueffel, a Nazi war criminal in hiding.

While investigating the contamination and mutation of marine life in China, Dr. Quest discovers a secret missile base (operated by a rogue general and protected by treetop-posted guards) hidden deep within a local swamp.