There was laughter when a strange-looking, almost sinister robot swathed in a trenchcoat confronted Astro Boy and Doctor Elefun, demanding that they accompany him to an unknown kingdom at the bottom of the sea. Intrigued by the prospect of it, Doctor Elefun persuades Astro Boy into joining him and the robot. Soon they are hurtling in a peculiar ship straight toward the bottom of the ocean where lo and behold- a magnificent city of the future rises, splendid and shining beneath a great glass dome! The visitors from Earth are dumbfounded, until they realise the purpose of the visit. The city is inhabited entirely by robots – robots who believe they created themselves; who believe that they are perfect and are dedicated to wiping out the animalistic human beings that people the continents above! Why have they brought Astro Boy here? To show him that he was created to be nothing more than a tool for his selfish masters; to convince him that he should join their great crusade to destroy the menace of humanity! Astro Boy’s attempts to reason with the robots prove futile! At last he proposes a contest; a personal contest between him, the pinnacle of human art and science, and the greatest robot his self-made adversaries have to offer. It’s agreed. Several tests for intelligence and creativity are staged. When Astro Boy wins each one, his powerful opponent seeks to destroy him until the bottom dweller learns that he was created not by robots, but by a man, and that he is really a robot bomb!