Well its a quiet night here at the cafe. Just afew of the gang inhouse tonight. The old standbys. And they all voted on an old goldie from down in the cafe vaults.
"Gort! Klaatu barada nikto!"
Thats right folks the day the Earth stood still!
For you youngsters; "Klaatu (Michael Rennie) arrives in a flying saucer-like spaceship and lands on the Ellipse in President's Park, Washington, DC. He declares he has come in peace on a mission of goodwill; he holds up and activates a small device that opens with a snap. Before he can explain what it is, Klaatu is shot and wounded by a nervous soldier, who assumes the device is a weapon. In response, a large robot called Gort steps out of the spaceship and melts all weapons present without harming the soldiers, until the wounded Klaatu orders him to cease. Klaatu explains the "weapon" was a gift to the President and could have been used to study the other planets.
He is taken to Walter Reed Hospital and quickly recovers. While there, Klaatu meets the President's secretary, Mr. Harley, but is unable to convince him to organize a meeting of world leaders. Klaatu suggests the United Nations, but is told not all the world's countries are represented there, and later, that world leaders cannot even agree on a meeting place for such a momentous occasion. When Klaatu makes known his wish to live amongst ordinary people, to understand them better, Mr. Harley rebuffs him and implies that the alien patient is a prisoner. Later, Klaatu easily escapes into the night.
He goes to a boarding house and tells those living there his name is "Carpenter", taking the name from a laundry label on a suit he has taken. Among the residents are Helen Benson (Patricia Neal), an employee of the United States Department of Commerce, and her son Bobby (Billy Gray). Helen is a widow; her husband was killed at Anzio during World War II. The next morning, Klaatu listens to the radio commentator and breakfast table banter of the boarders. They wonder whether the spaceship is from outer space or perhaps the work of the Soviets. When Helen's boyfriend, Tom Stephens (Hugh Marlowe), plans a day-trip getaway for the two of them, Klaatu offers to take care of Bobby.
Bobby gives Klaatu a tour of Washington, D.C., including a visit to the grave of his father in Arlington National Cemetery, where Klaatu learns with dismay that most of those buried there were killed in wars. The two next visit the Lincoln Memorial and the heavily guarded spaceship where Gort stands motionless. Klaatu, impressed by the inscription of Abraham Lincoln's Gettysburg Address, is hopeful that there may be minds on Earth wise enough to understand his message. When he asks Bobby to name the greatest person in the world today, Bobby mentions a leading American scientist, Professor Barnhardt (Sam Jaffe), who lives nearby.
Bobby takes Klaatu to Barnhardt's home. The professor is absent, but Klaatu goes into his study and helps solve an advanced mathematical n-body problem written on a blackboard, before leaving his address with the housekeeper. Later, government agents escort Klaatu to see Barnhardt. Klaatu warns the professor that the people of the other planets know that human beings have developed atomic power and will not allow this to endanger them. Barnhardt offers Klaatu the opportunity to speak at an upcoming meeting of world scientists he is organizing; Klaatu accepts. Barnhardt is stunned when Klaatu declares that if his message is rejected by the leaders of the nations, "Planet Earth will be eliminated." The professor soberly pleads that Klaatu first provide a minor demonstration of his power as a warning. . . I won't ruin the ending