The 100 is the first novel in The 100, a series of post-apocalyptic science fiction series by American author Kass Morgan. The novel is set approximately 300 years after a nuclear cataclysm rendered the Earth uninhabitable. Humanity, however, has survived for generations on three large spaceships: Phoenix, Walden, and Arcadia. With life support on the ships dwindling, 100 prisoners under the age of 18 are sent down to Earth to find out if it has become survivable.