Later, while Adams tries to persuade Altaira to leave, Ostrow sneaks away to use the Krell educator. He is fatally injured, but with his dying words, Ostrow tells Adams that the great machine was built to create anything from thought alone. He says that the Krell forgot one thing, however: "monsters from the id". Their own base subconscious desires, given free rein and unlimited power by the machine, brought about their quick extinction. Adams asserts that Morbius' subconscious mind created the creature that killed the original expedition and attacked his crew. Morbius refuses to believe him.