In times long past, this planet was the home of a mighty, noble race of beings who called themselves the Krell. Ethically and technologically they were a million years ahead of humankind, for in unlocking the meaning of nature they had conquered even their baser selves, and when in the course of eons they had abolished sickness and insanity, crime and all injustice, they turned, still in high benevolence, upwards towards space. Then, having reached the heights, this all-but-divine race disappeared in a single night, and nothing was preserved above ground.
Commander John J. Adams: Nice climate you have here. High oxygen content.
Robby the Robot: I seldom use it myself, sir. It promotes rust.