The story follows the adventures of two Earthmen, Captain Eric Carstairs and his friend, Professor John Taine, as they travel to the planet of Peril, located in the star system of Alpha Centauri. The planet is inhabited by a race of intelligent, humanoid aliens called the Perilians, who are ruled by a cruel and oppressive tyrant, the Grand Khan. The two Earthmen soon find themselves embroiled in a struggle to overthrow the Grand Khan and free the Perilians from his tyranny. Along the way, they must battle giant monsters, face off against powerful enemies, and discover the secrets of the mysterious planet. With the help of their newfound allies, they must find a way to save the planet and its people from the Grand Khan's tyranny.
By Otis Adelbert Kline · First published 1929 · Genre: Science Fiction, Adventure, Fantasy · 19 chapters