Forbidden Planet was MGM’s lavish entry into the pantheon of great 1950’s Science-Fiction Films. The plot was loosely based on Shakespeare’s “The Tempest” (I never read it either, but there’s a recent film version with Helen Mirren, maybe I should check it out). The film begins in space, aboard Starship C-57D as it approaches the planet Altair IV. The crew is tasked with determining the fate of a previous expedition to same planet (some 20 years before). Prior to landing, they are contacted by a survivor of that expedition, the scientist Morbius (one of the coolest Science-Fiction names, by the way, up there with Klaatu), and are warned not to land, due to some unspecified danger. Of course, they stubbornly land anyways, and are greeted by Morbius, his nubile young daughter Altaira and their super cool robot named Robby. They appear to be living comfortably in an ultra modern house beautifully situated in the alien landscape of Altair IV (sort of looks like the desert southwest but with green skies). But, there is a terrifying invisible monster lurking out there, which seems bent on killing members of the crew of C-57D (but does not seem to have a beef with Morbius & his daughter). Also, it turns out, Morbius’s house is situated above the remnants of an extinct civilization called the Krell, and in an impressive reveal, Morbius gives the Captain and a few crew members a tour of a vast (still functioning) underground Krell city which fucking blows their minds to say the least. Morbius demonstrates a Krell machine which sort of lets you fabricate shit right out of your own mind. Turns out, that machine, why the Krell went extinct, and what the hell the invisible monster is, are all related.
Here’s an interesting documentary on Forbidden Planet (in 2 parts):
One of the ground breaking things about the film was the the electronic “score” created by Bebe and Louis Barron (which is discussed in part 2 of the documentary). Here’s a great short video where the great Sound Designer Ben Burtt re-creates some of the sound for Forbidden Planet, explaining how it was done using 1950’s technology: