Written in collaboration in 1922 by the author of Felifax, this five-volume saga (of which this is the fourth), purporting to chronicle the early years of the 21st century, takes place in a quasi-utopia-like Earth, where, thanks to the genius of master scientist Oronius, humanity has mastered natural forces. However, Oronius' former colleague Otto Hentzen, a mad scientist who has allied himself with the beautiful, deadly Princess Yogha, has sworn revenge on the master scientist. After the worldwide cataclysm that devastated the Earth, Oronius and his friends discover an advanced civilization of giant insects long buried in Antarctica. The Polars, aided by Hantzen and Yogha, launch an attack against Humanity, increasing the intelligence of animals, who then rebel and enslave mankind, turning the world into a "Planet of the Beasts." Oronius eventually escape from his enemies and enlists the help of the United States to fight the giant insects…