Atherton consists of 3 worlds - it's actually 3 different levels of land all on one planet. The top level controls all the water to the other two levels and demands that the 2nd level produce food for the top level, delivered by an elaborate rope and pulley system as there is no other way to scale the cliffs to the top. No one knows what is on the 3rd or bottom level as it is also impossible to get to. Edgar lives on the 2nd level and he is an excellent climber. He finds a book hidden in the cliffs and decides to climb the cliffs no matter what in order to find someone to read the book for him.