It is the 23rd Century and the United Planets starship C-57D arrives at Altair IV to investigate the loss of contact with an expedition there 20 years before. On the surface is Doctor Edward Morbius (Walter Pidgeon) from that expedition, and he warns the C-57D not to land because of the danger. Commander John J. Adams (Leslie Nielsen) pays no attention.

The ship, a flying saucer, lands. Adams, Lieutenant Jerry Farman (Jack Kelly), and “Doc” Ostrow (Warren Stevens) are met by Robby the Robot (Body by Frankie Darro, voice by Marvin Miller), who takes them to see Morbius. He describes how the previous explorers were killed by a planetary force and their ship, the Bellerophon, was vaporized as it tried to escape the planet. Only Morbius, his wife who died later, and their daughter Altaira (Anne Francis) were immune. Morbius offers to help the visitors to take off safely, but Adams waits for instructions from Earth.

The next day, Lieutenant Farman tries to kiss the innocent Altaira and is dressed down by Adams. He criticizes Altaira for her revealing clothing and she designs something more conservative. That night, an invisible intruder attacks the camp and destroys some equipment. Adams and Ostrow try to get an explanation from Morbius in the morning. Adams talks to Altaira and kisses her himself. (?) Then he disintegrates her pet tiger, which attacks them.

They learn that Morbius has been studying the Krell, a highly advanced alien race that died suddenly 200,000 years ago. In a Krell lab, he demonstrates a device capable of enhancing intelligence capacity. Morbius himself barely survived using it, but his intelligence doubled. They tour a giant Krell machine complex beneath the surface, in a 20-mile-wide cube powered by 9,200 nuclear reactors. Adams demands this knowledge be turned over to Earth authorities, but Morbius refuses, protesting that mankind is not ready.

Adams puts up a force-field barrier around the ship, which fails to stop the invisible creature from entering and killing Chief Engineer Quinn (Richard Anderson). Morbius warns of his premonition of more attacks. That night, the creature returns, outlined and visible in the force-field. Blasters are useless and it kills three crewmen. Altaira screams in her sleep and awakens Morbius as the creature vanishes.

While Adams, the next day, tries to persuade Altaira to leave for her safety, Ostrow sneaks out to use the Krell educator and is killed. His dying words are a warning about Monsters from the Id. It seems the Krell’s own subconscious desires, enhanced by the machine, did them in. Morbius objects that there are no Krell now, but Adams suggests that Morbius himself wiped out the original expedition and is responsible for the recent attacks. Morbius scoffs at this.

Altair informs Morbius that she wants to leave with Adams. Robby detects the creature’s approach. Morbius orders Robby to kill it, but Robby replies that it is a creature of Morbius’ mind, and he shuts himself down rather than injure his master. Adams, Morbius, and Altaira hide out in the Krell lab, but the creature melts the walls. Morbius finally understands, confronts the creature, but is fatally injured. The monster vanishes. Morbius tells Adams how to activate a planetary self-destruct sequence. From the ship, at a safe distance, they watch the planet explode.

I think the Krell, as aliens go, are pretty bad, having wiped themselves out and, even if not intentionally, leaving a fatal trap for future explorers. The film was produced by Nicholas Nayfack for MGM, the story loosely based on Shakespeare’s The Tempest. It was the first film to show humans in their own starship, far from Earth. The striking electronic score by Bebe and Louis Barron, who were discovered performing at a nightclub in Greenwich Village, was ground-breaking. The Monster from the Id and many other laser effects were created by Joshua Meador of Walt Disney Studios. It roars and shakes its head exactly like Leo, the MGM mascot. The Morbius family’s garden is a leftover from the Munchkin Village set from the Wizard of Oz, which was filmed on the same sound stage. This was the first high-budget science-fiction film. It was Leslie Nielsen’s first role, and we must have self-control now not to laugh at him.

The film was nominated for the visual effects Oscar. Reviews were generally raving, describing the movie as weird but fascinating and highly imaginative. It was banned in Spain because of the mini-skirts Anne Francis wore, which were designed by Helen Rose, who also designed Elizabeth Taylor’s dress for her wedding to Nicky Hilton and Grace Kelly’s dress for her wedding to Prince Rainier. At least it gave Anne Francis something sexy to wear on the posters as she was carried off by the “threatening” robot monster. Anne Francis thought the secret of success of the film was that all the actors were told to take it seriously. The Doctor Who episode Planet of Evil was consciously based on Forbidden Planet. The spaceship was used on the Twilight Zone at least a dozen times from 1959 to 1963.

Robby was the first robot character to have any character in a movie. He was operated by a small actor named Franklin Darro, who was fired for falling over in the suit after a five-martini lunch. The robot cost a quarter million dollars, which was real money in those days. It was sold later for five million, a million more than the Maltese Falcon statue, and it is now in the private collection of horror-film director William Malone. A copy of it is owned by George R.R. Martin. Robby had a long career appearing at grand openings and on TV shows, including Perry Como, Hazel, Dobie Gillis, The Twilight Zone, Mork and Mindy, Wonder Woman, The Man from Uncle, Lost in Space, and Loveboat. Marvin Miller, Robby’s voice, narrated the movie trailer. Directors like James Cameron and J. Michael Straczynski have talked of doing a sequel, but that did not happen. Perhaps we should be grateful.