The public hoped after the spaceship carrying Klaatu and the robot Gort launched from the Ellipse just south of the White House, that it was all over. The newspapers, radio, and TV broadcasts reported the full text of the speech the alien had given to the international group of scientists assembled at the park by the esteemed physicist Professor Jacob Barnhardt. For a time, the citizens of the world were terrified that the Earth would be destroyed if the Americans and Soviets continued their efforts to develop nuclear power and advanced rocketry.
But with the passing of weeks and then months, when nothing else happened, humans, being who they are, paid less and less concern to the dire warning of the man from another planet and got on to the next crisis or fad.
However, governments capable of observing orbital space and a small but select group of scientists knew that when Klaatu departed, he left something behind or rather six somethings.