"Psychlos" is a science fiction novel written by L. Ron Hubbard, published in 1950. The story is set in a post-apocalyptic Earth, where an alien race known as the Psychlos has taken over the planet. The narrative follows a human protagonist, Johnny Goodboy Tyler, who seeks to free humanity from the oppressive rule of the Psychlos. The novel explores themes of oppression, resilience, and the struggle for freedom. It delves into the interactions between humans and the Psychlos, highlighting the differences in their cultures and values. "Psychlos" has gained notoriety for its ambitious world-building and has been adapted into a film in 2000.