Atherton is a artificial planet with its own atmosphere orbiting above earth (The Dark Planet) . It has a small human population, and a large lake in the center filled with edible, aquatic centipedes known as cleaners. Atherton was created by the genius Dr. Harding, as an escape from the pollution on the Dark planet.
Originally, Atherton was composed of 3 distinct circular sections, arranged concentrically, which were from bottom to top the flatlands, tabletop, and the highlands. The flatlands was inhabited by cleaners, and provided most of the islands gravity. Tabletop was inhabited by humans which lived in settlements known as the Grove, the Village of rabbits, and the Village of Sheep. These settlements harvested food and traded them to the Highlands for water. The highlands were the peak of Atherton, and its inhabitants were considered nobles. Horses lived in the highlands. The highlands could control the water supply, and thus forced the tabletop to send up food in return for water.
In The House Of Power, the upper levels of Atherton begin sinking lower, and the water supply drastically increases without control. This leads to increased contact between the levels. The creator of Atherton, Dr. Harding, reveals that Atherton is in fact incomplete and undergoing metamorphosis.
In the Rivers of Fire, Atherton's center begins sinking below the flatlands. Cleaners begin flooding into tabletop and the highlands, and the water supply increases even more. Eventually, tabletop and the highlands become a central lake, inhabited by the cleaners. Meanwhile, a new side to Atherton is revealed as a group escaping the flood journeys deep into Atherton's interior. There, they discover vast caves filled with new creatures, such as the Fire bugs, the Nubian, and the lava eel. Eventually, the group makes its way to the flatlands, where the other remnants of Atherton civilization have gathered and begun to rebuild.
For more information, go to http://www.hachettebookgroup.com/features/athertonseries/atherton.html