Far in the future, a teenaged girl named Ellis Antlers is the last person left on Topside, her side of the planet. After meeting the Guardian of Imaginedland and falling through the Earth, Ellis finds that her Topside compatriots have been there first, and all have been brainwashed in the sinister land of Purplevania. With a walrus-mustachioed Anglo-Siberian named Borax Meerschaum, the Prince of Whales and Leader of the Overground; his shape-shifting...