Forbidden Planet is the most ambitious Shakespearean adaptation in science fiction — and one of the most intellectually honest. It does not merely transpose The Tempest into space: it uses the play's architecture to ask what the story means when stripped of its magic and filtered through Freudian psychology. What follows is a systematic account of what survives the translation, what is transformed, and what those transformations reveal.
▸ Click a row to read the analysis
Select a character pairing above to read the comparative analysis.
The divergences are not failures of fidelity. Each departure from Shakespeare is a deliberate interpretive choice that reveals something about the 1950s cultural moment — or about the deeper logic the film is drawing out of the play.
Prospero renounces his magic and returns to Milan to resume his dukedom. His book is drowned; his staff broken. Caliban is left on the island with a new freedom — Prospero's departure removes the master. Ariel is freed. Ferdinand and Miranda are united. The wrongdoers are confronted but forgiven. It is a comedy's ending: restoration, reconciliation, return.
Crucially, Prospero's renunciation is voluntary and complete. He chooses to re-enter the human world, to set aside power, to acknowledge the limits of magic. His epilogue — 'release me from my bands / with the help of your good hands' — is a request for the audience's forgiveness. He knows what he has been.
Morbius does not choose to renounce. He is confronted with irrefutable evidence of what his unconscious has done and, in a supreme act of will, attempts to deny the Id monster — which kills him. The machinery that sustained his intellect for 20 years destroys him the moment he withdraws his unconscious cooperation. He does not return to Earth. He dies on Altair IV and takes the planet with him.
There is no forgiveness — Morbius cannot be forgiven by a crew who don't know what killed them, and cannot forgive himself for what he didn't know he did. Altaira escapes, but as an orphan, not a bride returned to a restored order. The planet is annihilated rather than re-inhabited. Nothing is reconciled. Everything is destroyed.
Shakespeare's Tempest is a late play written by a man laying down his work — Prospero's renunciation of magic is widely read as Shakespeare's own farewell to the theatre. The ending is elegiac but finally peaceful: the wizard goes home. The colony is abandoned; civilisation asserts its claim over the enchanted island.
Wilcox's ending refuses this consolation. Morbius cannot go home because he never truly wanted to. His unconscious — his Id — betrayed this desire for two decades before his conscious mind admitted it. And when his conscious mind finally does confront it, the machinery that made him exceptional is the same machinery that kills him. Power and guilt are the same substance.
More significantly: the Krell's mistake and Morbius's mistake are identical. A civilisation annihilated itself by amplifying its own unconscious; a man destroys himself by the same mechanism, on the same planet, with the same technology. The ending is not tragic in the Shakespearean sense — it is cautionary. The audience survives. They are invited to draw the conclusion that both the Krell and Morbius could not: that there are things the unconscious mind should never be given the power to do. In 1956, with the hydrogen bomb a decade old, this was not an abstract warning.