Forbidden Planet

In the early 23rd century, the United Planets Cruiser C-57D is sent to the planet Altair IV, 16 light-years from Earth, to investigate the disappearance of a colony expedition sent 20 years earlier. Before landing, the ship is contacted by Dr. Edward Morbius (Pidgeon), who warns them to stay away.Upon landing, the ship is met by Robby the Robot, who takes Commander John J. Adams (Nielsen), Lieutenant Jerry Farman (Jack Kelly), and Lieutenant "Doc" Ostrow (Warren Stevens) to Morbius' home. Morbius explains to them that an unknown force killed all of the other members of his crew and destroyed their starship, the Bellerophon. Only Morbius, his wife (who died later of natural causes), and his daughter Altaira (Francis), now 19 years old, survived. He fears that the crew of the C-57D will suffer the same fate. Altaira has never met a man besides her father, and is interested in getting to know the new arrivals and learn about human relations.Morbius explains that he has been studying the Krell, the natives of Altair IV who, despite being far more advanced than humanity, had all mysteriously died in a single night 200,000 years before. He shows them a device that he calls a "plastic educator". Morbius notes that the captain of the Bellerophon tried it, and was killed instantly. When Morbius used it though, he barely survived, and doubled his intellect in the process. He claims that that enabled him to build Robby and the other technological marvels in his home. Morbius then takes them on a tour of a vast cube-shaped underground Krell installation, 20 miles on a side and powered by 9,200 thermonuclear reactors, which has been operating and self-repairing itself since the extinction of the Krell. When asked its purpose, Morbius admits he does not know.One night, a valuable piece of equipment in the ship is damaged, though the sentries report they saw no intruders. In response, a force-field fence is set up to protect the ship. The protection proves to be useless; the unseen thing returns, shorts out the fence, and kills Chief Engineer Quinn (Richard Anderson). Dr Ostrow examines footprints left after the attack and is confused, saying that the creature appears to violate all known evolutionary laws.The intruder returns the following night, and is discovered to be invisible - its appearance only revealed by its outline in the force-field beams. Several crew members are killed in a massive firefight with the monster. At his home, Morbius is in the Krell lab and subconciously knows that the attack is underway but cannot stop it. His trance is broken by Altaira's scream. At that moment, the creature vanishes.Later while Adams confronts Morbius at the house, Ostrow sneaks away to use the educator, with fatal results. Just before he dies though, he manages to tell Adams that the underground installation was created to materialize anything the Krell thought of, but they had forgotten "Monsters from the id!" Morbius objects, pointing out that there are no Krell left. Adams replies that Morbius' mind - expanded by the plastic educator and thus able to interface with the great Krell machine - subconsciously created the monster that killed his shipmates 20 years earlier, after they had voted to return to Earth. Morbius refuses to believe Adams' theory.When Altaira declares her love for Adams in defiance of her father, the monster comes for them. Morbius commands Robby to kill it, but the robot freezes, recognizing that the monster is an extension of Morbius. The creature breaks into the house and melts through the nearly-indestructible door of the Krell vault where Adams, Altaira and Morbius have taken refuge. Morbius finally accepts the awful truth and tries to renounce his creation. When he is mortally injured, the monster disappears. As Morbius lies dying, he directs Adams to press a lever which sets the Krell machine to self-destruct. Adams, Altaira, Robby, and the surviving crew take off and witness the destruction of the planet from a safe distance in space.