When a boxing hopeful invents a powder that makes him invisible in the ring, he becomes middle-weight champ. He decides the speed limit doesn't apply to him, since he knows the police can't see him, but after waking from a nap he finds that the police have constructed a jail around him.; A pilot who breaks the sound barrier hears voices plotting an invasion of America which turn out to be from Napoleon.; A circus clown is unaware that his performance is being viewed by an appreciative alien ambassador.; A father of a little boy finds out that even toys have parents too.; When an atomic war destroys civilization, the primitives who are left use an old phonograph recording of a message of peace to psyche themselves up for the war raids they inflict upon neighboring tribes.