Day the Earth Stood Still, The (1951): Robert Wise’s Seminal Sci-Fi Film, Starring Michael Rennie and Patricia Neal

Robert Wise’s “The Day the Earth Stood Still,” one of the seminal sci-fi films of the 1950s, tells the story of a humanoid alien who comes to Earth to warn its leaders not to take their conflicts into space, or else they will face devastating effects. Produced at the start of the Cold War and the development of the first hydrogen bombs, this timely film deals with the fear of global annihilation.
For the film, screenwriter Edmund H. North adapted Harry Bates’s short story “Farewell to the Master,” and many people recall the memorable score, composed by the genius Bernard Herrmann, which was notable for its use theremins.
On the surface, the story appears simple. When a flying saucer lands in Washington, D.C., its pilot Klaatu (Michael Rennie) declares he has come on a mission of goodwill. However, after opening a small device with a snap, he is shot and wounded by a soldier who mistakes it for a real weapon.
As a result, the large robot Gort steps out of the spaceship and melts the weapons without harming the soldiers–until Klaatu orders him to cease. Klaatu explains that the “weapon” was a gift to the President and could have been used to study life on other planets.
Taken to Walter Reed Hospital, Klaatu meets the President’s secretary, Mr. Harley, but is unable to convince him to organize a world summit. Klaatu suggests the United Nations, but is told it does not represent all countries; later on, the world leaders cannot agree on a meeting place. Klaatu proposes to live with ordinary people so that he can understand them better, but Harley rebuffs him; feeling like a prisoner, Klaatu escapes.
Dressed in the stolen coat of “Mr. Carpenter,” he goes to a boarding house as “Mr. Carpenter,” where he meets Helen Benson (Patricia Neal), a government employee who’s a widow, and her son Bobby (Billy Gray); the husband was killed in WWII.
When Helen’s boyfriend Tom Stephens (Hugh Marlowe) plans a day-trip getaway, Klaatu offers to take care of Bobby. The two then embark on a tour of the city, visiting the grave of Bobby’s father in Arlington National Cemetery, the Lincoln Memorial and the heavily-guarded spaceship where Gort stands on guard. When he asks Bobby to name the greatest person alive, Bobby mentions a leading American scientist, Professor Barnhardt (Sam Jaffe), who just happens to live nearby.
Upon arrival at Barnhardt’s home, the professor is not there, and Klaatu goes into his study and helps solve a mathematical on his blackboard, before leaving his address with the housekeeper. Later, government agents escort Klaatu to see Barnhardt, and Klaatu warns the professor that the people of the other planets are concerned for their own safety, because humans now possess nuclear power. Barnhardt is shocked, when Klaatu declares that if his message is rejected by the leaders of the nations, “Planet Earth will be eliminated.”
Klaatu returns to his spaceship that night, while Bobby trails him. Meeting Helen at work, Klaatu rides in an elevator that stops. He had suppressed electric power all over the world, except for hospitals and other crucial places.
Klaatu then discloses a code, “Klaatu barada nikto,” that Helen must use if something happens to him. Battling fear, Helen does as Klaatu instructed. Gort retrieves Klaatu’s corpse and brings him back to the spaceship where he is miraculously brought back to life. Stepping out of the spaceship, Klaatu tells the scientists about Earth’s penchant for violence and warns that the people of Earth can either abandon warfare and peacefully join other nations or be destroyed.  His last words before departing are: “The decision rests with you!”
Cast
Klaatu and Mr. Carpenter (Michael Rennie)
Helen Benson (Patricia Neal)
Tom Stevens (Hugh Marlowe)
Professor Jacob Barnhardt (Sam Jaffe)
Bobby Benson (Billy Gray)
Mrs. Barley (Frances Bavier)
Gort (Lock Martin)