1950s sci-fi films often feature campy special effects and hostile outsiders from another planet trying to invade this one but Forbidden Planet stands out from the crowd in that it features neither of these things. MGM poured a lot of money into the excellent model work and borrowed a Disney man to work on the animated laser blasts and the famed "Monsters from the ID" and the threat comes not from "out there" but from deep within the mind of man.
In the 23rd Century, a star ship led by Commander John Adams (Leslie Nielsen) is sent to the distant planet of Altair 4 in order to find out what happened to an expedition who landed there 20 years earlier. On arrival the crew are met by the only survivors, Dr Morbius and his daughter Altaira, and their robot servant, Robby. Morbius tells them that his shipmates and their craft were destroyed by a planetary force when they tried to leave. The same force starts to attack Adams and his crew and ship but is it a force which may have a source closer to home than someone would like to admit?
The script for Forbidden Planet is both one of the best and weakest things about the film. The themes explored are serious and intelligent, aimed at adults, not the teenage drive-in crowd of The Blob, and are engaging and thought provoking. But it is also relentlessly talky at times, giving the film an often sluggish paced, something not helped by the slightly flat and stilted performances of the leads.
However, these occasional lapses are more than made up for by the sumptuous visuals, whether it is the spacecraft model work, the huge, imposing and beautifully realised Krell underground cities (structures that completely dwarf their human interlopers), or the eerie and disturbing animated silhouettes of the Id monster, courtesy of Disney’s Joshua Meador, who was loaned to MGM for the film.
The story is not entirely original of course. Forbidden Planet often gets branded as a space opera version of The Tempest, and while that is not strictly true, it does share some similarities with Shakespeare's play. The Tempest centres on Prospero, a magician exiled to an island with his daughter Miranda by his brother Antonio who then steals his title and property. Prospero uses his powers to cause a storm that shipwrecks Antonio, trapping him on the island where he can take his revenge. Morbius is the Prospero character with Altaira as Miranda, and Altair 4 stands in for Prospero's island. After that the comparisons don't really work as Adams and the crew are strangers to Morbius, and he is not driven by revenge, rather a desire to be left alone to carry exploring the planet and the Krell, the now extinct civilisation that lived there previously.
Forbidden Planet works much better if you judge it as a piece of work in its own right, and as a time capsule of the ideas, attitudes and obsessions of the time in which it was made. The first of these obsessions is Freudian psychoanalysis, which by the 1950s had come out of the consulting room and into popular culture, in particular the movies, through the work of directors such as Hitchcock. It is made explicit in Forbidden Planet through talk of "Monsters from the Id". The Id is what Freud thought of as the primitive, instinctive, often illogical aspect of our personality that demands immediate satisfaction, regardless of the consequences. Morbius thinks both he and the Krell have outgrown this, but it soon becomes apparent, particularly when handsome space pilots take a shine to his daughter, that he has not, and the raging torrent in his psyche takes a more literal and deadly form when linked to the highly advanced Krell technology.
Forbidden Planet is also very much of it's time in its look and attitudes. The Flying Saucer that the crew arrive in is another 1950s icon, albeit one here used by mankind rather than little green men. The film has some of the 50s can-do optimism of a country riding high from the post-war euphoria, with a new generation of pioneers, rolling up their sleeves and carving out new worlds. The craft is run like the ships and subs that some of the audience may have served on during the war 10 years earlier, even down to the cook with a taste for bourbon.
Robby the Robot is also a very old fashioned idea of a robot, basically a butler with a deadpan tone of voice. Although a wildly impractical design, he would go to become an iconic figure in further films and TV shows, and here, more importantly, plays an important role, driving the plot forward with his manufacturing capabilities and programmed attitudes towards human life. The deadpan tone also provides some comic relief to the sometimes very serious onscreen talking.
The astonishing, unsettling soundtrack is the work of electronic music pioneers Bebe and Louis Barron. It breaks all the rules of what a soundtrack should be in two big ways. Firstly it is entirely atonal, being composed and performed on oscillators made by the Barrons, and fed through echoes and tape loops. Secondly, by having their work represent everything from the ambient noise of the Krell buildings, the roar of the monsters and the ship’s engines, but also having it underpin key scenes to add to the tension, they blur the lines between diegetic and non-diegetic audio.
Forbidden Planet had a further influence beyond this, leaving an undeniable mark on the whole sci-fi genre. It paved the way for serious, adult sci-fi such as 2001: A Space Odyssey, as well as providing the template for Star Trek. The film and TV show both feature a ship run like a military craft, exploring new worlds and investigating mysteries, but using a scientific approach to explain things. In addition, the human drama in Trek and Forbidden Planet centres around the three main crew members, the First Officer, the ship’s doctor, and the steely, unflappable captain with an eye for the ladies.