With the continuous development of science and technology, the earth on which human beings depend for survival has been more and more seriously polluted and threatened. One day, a huge flying saucer appeared over the earth, causing panic among people all over the world, and no one knew what impact this uninvited guest would have on their fate. The UFO finally landed in the middle of Washington Park in the United States, and the local police and army turned out. The UFO was surrounded by heavily armed soldiers and curious people. After a two-hour standoff, the ladder slowly protruded from the UFO. With the opening of the hatch, a human-like alien Cratto (Michael Rennie) and a metal-covered robot appeared in front of the crowd. These two aliens seem to have come for the fate of the earth. they showed friendship, but did not get what they deserved in return. This film won the Golden Globe Award for Best Film Promotion of International understanding in 1952.