Atherton was once a magnificent three-tiered world, but few inhabitants know the truth of its dark origin: it is a giant man-made satellite, created as a refuge from a dying Earth. Now this strange place is torn apart--its three lands, formerly separated by treacherous cliffs, have collapsed and collided. But a gifted climber and adventurous orphan boy, Edgar, is determined to discover the secret of Atherton's survival, and embarks on a life-or-death quest to find its mad maker.