A strange rocket from outer space crashes on earth and the first man to investigate is Professor BooBoo who finds the plans for a super duper robot. BooBoo hires Doctor Elefun and the Institute of Science to build the robot for him. Astro Boy and Astro Girl, left alone in the laboratory, play with the controls of the robot builder and accidentally complete the assembly of the robot. Astro Boy fights the robot and is saved from destruction by Doctor Elefun. Astro Boy insists that the robot is too dangerous. Doctor Elefun disagrees and intends to turn over the robot to Professor BooBoo. Astro Boy, realizing that it’s the only way to save mankind from the robot, steals its head and hides it on a distant island. Professor BooBoo sends the robot in search of its head and only after a tremendous battle can Astro Boy defeat the robot. Having proved that it was indeed a vicious robot he is forgiven for stealing the head and once more is hailed a hero.