 The last spaceship to leave Mars headed for Earth is stopped and searched by Martian soldiers, who are looking for three saboteurs who destroyed a Martian city.They are not found, and the ship continues towards Earth.On board the space ship, a business man by the name of Thacher meets a young woman and two men, who tell that they are the people sought by the Martians, and proceed to tell Thacher the story of how they did not destroy the Martian city, but used a device to reduce the entire city to fit in a tiny globe, which they smuggled on board the ship.