Humans and their genetically altered descendants struggle to find their place in a universe controlled by a benevolent artificial intelligence in this brilliant classic of future speculation. On a far-future Earth, a linked system of artificial intelligences called the cybercosm runs the planet and the universe far more efficiently than any flesh and blood ruler ever could, in essence rendering the human race obsolete. On the Earth's moon, genetically engineered Lunarians carrying the DNA of Dagney Beynac-a descendant of the legendary Anton Guthrie, founder of the powerful and visionary Fireball Enterprises-struggle to preserve their lives, their freedom, and their satellite's resources in the face of threats posed by encroaching humans and controlling machines. Over a span of five centuries, tensions have increased in the wake of the political and technological revolutions that reshaped their universe. And suddenly radical change is in the offing once more, as a secret kept hidden since the earliest days of Lunar colonization is about to be revealed-one that could effectively shut down the cybercosm and plunge the universe into chaos.