A super-powered girl from the year 100,000 arrives and shows up Captain Comet at every turn.; Captain Robert Trent is transported from the Revolutionary War into the future of 1952 where he gathers information on future technology to help George Washington's army in his own time. But when he returns, none of the future inventions work and Washington dismissed him as a madman.; Bob Tarrant experments with his television set until he can receive transmissions from Mars. When washed-up movie director Eric Mills learns about this he kills Tarrant so that he can use the Martian transmissions as the basis for a new movie. However, he finds out that the Martians were using Tarrant, and now him, to help them invade Earth.; Derek Blake discovers the secret of Elmo the Great's powers.; Depiction of four of the greatest scientific discoveries in history, accompanied by a request for readers to send in their own lists of the four greatest discoveries.