The story takes place in the future, when people are colonizing other planets in the Solar System. A soldier from a unit stationed on Venus is sent to retrieve a crystal that holds strategic importance for humans but falls into a trap set by the native lizard-like people – a labyrinth with invisible walls.
The original version of the story, written by the young Kenneth Sterling (based on the idea from Edmond Hamilton's story "The Monster-God of Mamurth"), was half as long. Lovecraft rewrote the work, preserving as many original elements as possible.
The writers adorned "In the Walls of Eryx" with playful references to known individuals in their surroundings (for example, "effjay weeds and slimy ackmanths" are references to the disliked Forrest J Ackerman).
