A catastrophic event renders the Earth a ticking time bomb. In a feverish race against the inevitable, nations around the globe band together to devise an ambitious plan to ensure the survival of humanity far beyond our atmosphere: in outer space. Only a handful of survivors remain . . . Five thousand years later, their progeny—seven distinct races now three billion strong—embark on yet another audacious journey into the unknown, as they voyage to an alien world utterly transformed by cataclysm and time: Earth. Neal Stephenson combines science, philosophy, psychology, and literature in a magnificent work of speculative fiction that offers a portrait of a future that is both extraordinary and eerily recognizable.