Published in Comet #264-273 with 2 black and white pages each issue for 20 pages in all - Back on Earth, Dick Barton and his sidekick Snowy are invited to join a race car manufacturer to check out his new car, the Grey Ghost. An intruder is discovered on the premises and that is when Barton learns the facility is really a cover for a government lab developing a new atomic gun which enemy agents want to learn about.