"In the vernacular of space, this is T-minus one hour, sixty minutes before a human being named Major Robert Gaines is lifted off from the Mother Earth and rocketed into the sky, farther and longer than any man ahead of him. Call this one of the first faltering steps of man to sever the umbilical cord of gravity and stretch out a fingertip toward an unknown. In a moment we'll join this astronaut named Gaines and embark on an adventure, because the environs overhead - the stars, the sky, the infinite space - are all part of a vast question mark known as the Twilight Zone."
Gaines arrives back on Earth with his capsule in perfect condition, even though it had no landing gear. He notices several differences in this world, and decides he is in parallel world. He runs for his capsule, and is suddenly back in his capsule ready for splash-down. He tells General Eaton and Colonel Connacher the story, and that he was a colonel in the other world. They don't believe him, but then an officer comes in and says they picked up an unidentified spacecraft on radar for a few seconds, and the radio message was from a Colonel Robert Gaines."Major Robert Gaines, a latter-day voyager just returned from an adventure. Submitted to you without any recommendations as to belief or disbelief. You can accept or reject; you pays your money and you takes your choice. But credulous or incredulous, don't bother to ask anyone for proof that it could happen. The obligation is a reverse challenge: prove that it couldn't. This happens to be... the Twilight Zone."