While on an archaeological expedition to an ancient Mayan city in the Yucatán jungle, Dr. Quest is threatened by a greedy, ruthless British treasure hunter named Perkins and his native confederates, searching for riches in the same ruins.

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.

On a visit to the castle residence of a fellow Norwegian scientist, Dr. Quest must help protect his colleague's latest invention (the anti-gravity generator) from a cat-burglar, disguised as one of a row of seven gargoyles on the roof, who regularly breaks into the estate.