In Robert Wise’s cold war sci-fi classic, a flying saucer lands on Washington, D.C., and the alien Klaatu emerges with a message for the nations of Earth: stop warring with each other or the world will be destroyed to protect the more civilized planets of the universe. In addition to the obvious anti-nuclear message it contains, the film addresses the xenophobia in American culture that suspects those who are alien of spreading communist propaganda. The cast features Sam Jaffe (also a casualty of the blacklist) as the one scientist sympathetic to Klaatu’s cautionary message and Patricia Neal as the deliverer of the fateful message, "Klaatu barada nikto."