Planet Krel

Lore & Background

The Krell are a highly advanced race that mysteriously perished in a single night 200,000 years before the events of Forbidden Planet. Their underground machine, an 8,000-cubic-mile (33,000 km3) facility powered by 9,208 thermonuclear reactors, could create anything by mere thought anywhere on the planet. Dr. Edward Morbius, a scientist from the earlier expedition, studied Krell artifacts on Altair IV and used an intellect-enhancing device that doubled his mental capacity, though he barely survived the process.

The Krell's extinction is explained by Lieutenant Ostrow, who, after using the intellect enhancer, tells Commander Adams that the Krell forgot one thing: 'Monsters from the id.' The machine gave the Krell's own subconscious desires free rein with unlimited power, causing their own extinction. Morbius's own subconscious later creates a creature that kills expedition members and attacks Adams's crew.

Reader's Guide

The only human survivors on the planet are Dr. Morbius and his daughter Altaira, who live in a residence served by Robby the Robot. The planet is destroyed at the film's conclusion via a self-destruct system activated by Morbius.